8 ms·

Neat, but I've yet to see a single NFC use case that gets me anywhere near as excited as this author. Amiibo is a cool concept but obviously limited. I've used

Neat, but I've yet to see a single NFC use case that gets me anywhere near as excited as this author. Amiibo is a cool concept but obviously limited. I've used some writable tags for android settings changes and such years ago, but it just doesn't seem useful to me. Anyone know a killer use case I'm missing here?

MikeKusold 9y ago
The Yubikey NEO is the only NFC device that ever got me excited. It'd be nice to be able to store all my TOTP tokens on the device instead of the phone. Also, signing/encrypting text with PGP from the yubikey.
- hdhzy 9y ago
  Sadly there is no NFC token that supports 4096 bit RSA keys (I'm not even talking about EC keys). Fidesmo also has support for PGP/U2F over NFC.
  - brians 9y ago
    That's okay. RSA-4096 is suitable for long term secrets, but we're talking about authentication: typically signing short challenges, or DH key shares, for immediate verification. The requirements for that application are much lighter.
    - hdhzy 9y ago
      How do you authenticate through NFC PGP on Android? Is that something specific to your company or is there a public app that you're using?
      - xorcist 9y ago
        You can use something called Openkeychain on Android. It uses NFC Yubikeys for both PGP and SSH. Regarding your 4096 bit requirements, normally when you have those security requirements you would keep that key offline and use shorter lived 2048 bit keys for actual authentication. There is 4096 bit support with Yubikey 4 which unfortunately isn't offered with NFC.
        hdhzy 9y ago
        > You can use something called Openkeychain on Android. It uses NFC Yubikeys for both PGP and SSH. Okay, but open-keychain does not provide GUI to just sign or authenticate a user (you can sign as part of encryption process) so I was wondering if the parent was mentioning some application that interfaces with open Keychain (like k9mail or conversations.im) that gives just that: user authentication.
        hdhzy 9y ago
        > There is 4096 bit support with Yubikey 4 which unfortunately isn't offered with NFC. Yes, but OTG adapters work pretty well here or one can use Yubikey 4C if the phone has USB-C input.
- potatolicious 9y ago
  Absolutely this. SMS 2FA has security flaws that are becoming ever more evident - U2F via NFC is a great way to authenticate on Android, and I'm looking forward to having it on iOS as well. Edit: Welp. Looking at the U2F NFC spec it looks like some exchange with the key needs to occur, so without transmit access we're boned.
  - hdhzy 9y ago
    > U2F via NFC is a great way to authenticate on Android Unfortunately as far as I know only Yubikey NEO and Fidesmo card support it with Fidesmo being practically not usable. From https://www.fidesmo.com/nfc-u2f-android/ https://www.fidesmo.com/nfc-u2f-android/ : > Google’s own account security website, that on desktop allows you to register U2F devices, says that the feature is not compatible with the Chrome browser on Android. The account security site on GitHub seems to support the feature is a bit better. When pressing the button to add a token to the account it properly launches Google Authenticator to register the U2F device. When tapping the card and returning to the GitHub site however it doesn’t seem to have registered that anything has happened.
threeseed 9y ago
The biggest use case is probably for public transport. That's something where you are tapping on/off multiple times a day.
- givinguflac 9y ago
  Thanks for the reply. That does sound interesting and would certainly save a lot of disposable cards/tickets. Here's hoping more interesting uses come about with this increase in user base!
- maratc 9y ago
  Reading NFC transit passes doesn't sound too exciting. I mean, if a phone has an NFC chip, why not use the phone (plus an app) instead of a transit pass, tapping with your phone where you're expected to tap with your pass? This is like your phone wouldn't come with a music player, but would come with a full-fledged oscillograph instead.
  - ben1040 9y ago
    There is this Android app that allows you to read your transit pass to check the balance. It's pretty handy with a Clipper Card, for example. http://codebutler.github.io/farebot/ http://codebutler.github.io/farebot/ That said Chicago seems to have the most convenient system along the lines of what you're talking about -- you can use plain old tap and pay at the terminal with Apple Pay or Android Pay.
    - maratc 9y ago
      Reading balance is not too exciting, as I said. There doesn't seem to be any Android apps to let your phone function as a transit pass. I understand why it would be cool to let your phone replace your transit pass (as it's cool to let your phone replace your credit card), but I don't understand why it's cool to let your phone replace a transit pass reader.
      - cwyers 9y ago
rosser 9y ago
I suspect that the general lack of exciting things involving NFC might have a little bit to do with the fact that ~half the mobile audience couldn't do anything with them. That appears to have changed, so this consequence probably will too.
- MBCook 9y ago
  I always figured that was a big part of why QR codes didn't take off in the US (irony: Apple just added support in iOS 11). Even so, I'm kind of surprised that NFC hasn't come up with more interesting use cases than easy pairing and as a mode/location switch to mark you're at home/work.
- rtpg 9y ago
  if you could go beyond reading NFC tags (and also allow apps to use the NFC chip fully), then you remove the need for things like physical loyalty cards (like the Starbucks card). That's a really basic use case, but popular enough in Japan, where even old flip phones had NFC
- dilemma 9y ago
  You mean 10% of mobile users couldn't use NFC.
russell_h 9y ago
I don't know about a "killer use case", but I use NFC on my Nexus 5X all the time with my Yubikey Neo or to check the balance on my transit pass. I'm surprised iPhones were missing this, its not killer but its definitely useful.
ben1040 9y ago
One nice thing is bluetooth pairing. I bought a pair of Bose QC35 headphones recently. There is an NFC tag embedded in the headphones. I just had to tap my phone to the headphones and hit an "accept" button on my phone, and they were paired. Similarly a friend has a box plugged into their stereo that's essentially just an A2DP receiver with RCA outputs, and has NFC on it for pairing. I wanted to play some music on his stereo at a party, and all I had to do was tap my phone to the receiver and start up Spotify.
- MBCook 9y ago
  Apple sort of does something like this using BTLE on the 4th gen Apple TV as part of setup. It's kind of nice. But the idea of having it in headphone and routers and printers and other things? I can get behind that. Easy pairing is a use case that makes a ton of sense.
- rconti 9y ago
  Do you just tap, or do you have to launch an app first? I only ask because the bluetooth pairing process is already pretty painless (I have QC35 and an iPhone).
  - pathompong 9y ago
    I have Galaxy S7 and Sony SBH20. It's just a tap and they're paired.
  - JohnTHaller 9y ago
    You just tap if you have an Android phone with NFC. I purposely got a Bluetooth speaker with NFC to make pairing easy. Whether my girlfriend or I use it or most of our friends of we go to the park or bring it to a BBQ, it's much easier than the usual manual process required on iPhone.
  - rollingpebbles 9y ago
    I have an iPhone 6S, QC35 and a MBP 13 mid-2012. The Mac won't stay paired after booting and sleeping once. Only fixed by rebooting (kext reloading, process killing, bluetooth debug menu don't work). Also, it's annoying that it won't charge and stay powered-on simultaneously. Finally, there's ground loop noise originating from the iPhone if charging the iPhone & QC35 from the same source with using the audio cable together. ProTip: Apparently, the QC25 remote cable with buttons works on the QC35 too.
matthewcford 9y ago
Reading your blood sugar levels - https://www.freestylelibre.co.uk/libre/ https://www.freestylelibre.co.uk/libre/
stormbrew 9y ago
I think the thing is that uses of NFC tags aren't and shouldn't really be expected to be individually mind blowing. It's just something that can, in aggregate, make your life more pleasant by small increments that add up. Being able to read my balance on my clipper card with my android phone is something I miss since switching to ios. A promising thing I once used was wifi network ssid/password settings stored on an nfc tag on a wall (think restaurant). But, really, if there's a killer app it's probably payment and it's rolling out. Pretending that it's somehow distinct from other NFC use cases is pretty silly. It's just one of the most obvious ways it can be useful.
brad0 9y ago
I worked on some prototypes years ago on android that handled a payment from a contactless bank card on your phone. So in the payments space: - phone as a payment terminal - peer to peer payments I'm sure there's more than that but they're the low hanging fruit
- MBCook 9y ago
  Unfortunately it's read only so that stuff won't be coming to iOS.
  - brad0 9y ago
    I don't believe you need to write to the card in order to do payments. You send byte streams and it generates OTPs.
    - MBCook 9y ago
      I was thinking of cases where you may need to update the balance on the card. You're right, if you only used it as authorization I guess you wouldn't need write access.
jseliger 9y ago
Most modern cameras have, for the last couple years, used NFC to quickly and easily transmit photos from the camera to the phone. From what I understand, on Android this works pretty effectively. On iOS, however, weak NFC implementation means that one must use a kind of janky WiFi transfer system. It works, but it's kind of difficult to use and not very elegant.
- brad0 9y ago
  Are you sure it's transmitting over NFC? I thought NFC is quite a limited bandwidth connection. Maybe it's creating the initial connection over NFC and doing the actual transfer over wifi?
  - jseliger 9y ago
    Good point; you're probably right and I'm probably wrong, since I'm recalling seeing videos that demonstrate how NFC works w/ cameras on Android versus iOS. I do have an iPhone, so to get pictures from a camera I have to (usually) manually select the camera network, then go to the app, then start downloading. The clunky software camera companies ship doesn't help, of course. If I were in charge of a camera company I'd publish an API and SDK and welcome the world's many hackers to make the camera better, but alas I'm not and no one asks my opinion.
  - hengheng 9y ago
    NFC is used to transmit the login credentials, which is fairly nifty actually.
  - izacus 9y ago
    Android has a protocol called Android Beam where NFC is used to negotiate transfer which is then moved to either Bluetooth or WiFi Direct. That's probably what cameras are using. Between phones you tap them together while a picture / video is open (which is admittedly less elegant than AirDrop... although significantly more reliable in my experience).
zik 9y ago
In Australia most over the counter payments are done with NFC cards. Some banks allow this to be done with a wave of your phone so you don't need to carry credit cards at all.
- Andrenid 9y ago
  I just switched to this a week ago and loving it. I can go for walks and carry nothing but my phone, and still grab a coffee etc. My last week of spending has been done entirely via NFC payments.
adambrenecki 9y ago
Don't forget, it's not just about consumer applications. Anywhere you might use a QR code or traditional barcode, but you don't want to have to worry about the barcode becoming obscured or worn with use. I know we've thought about using them to track vehicles and some kinds of parts in the automotive retail company I work for, and there's probably plenty of other industrial applications for them.
giobox 9y ago
It reminds me of the ridiculous excitement over iBeacons when Apple announced their proprietary NFC-like tech a few years ago. Virtually every iOS dev I know bought some cheap iBeacons thinking "wow this is so cool" and never ended up building anything useful. I wasn't immune either, as the abandoned iBeacon in my desk drawer attests to. There's undoubtedly great use cases for NFC on phones (payments, travel passes, hotel room keys etc), but it's also a technology that often seems to attract developers solely because it seems 'cool', not because they have a problem that can be solved better with NFC than without it.
- dzhiurgis 9y ago
  iBeacon protocol is not proprietory. BLE covers larger area that NFC does not. I agree there aren't much real uses tho. But we might not know yet. For example LoRaWAN networks are deployed worldwide fairly quietly.
- abritinthebay 9y ago
  Beacons a) aren't Apple exclusive b) are really cool. The trouble is that the category of features they solve can often also be solved by GPS, Network, or other similar technologies. There are a myriad of cool things that Bluetooth Beacons can do but none of them are particularly consumer must-haves.
  - wensheng 9y ago
    Might be off-topic, but anyone know what other techs provide indoor distance tacking/localization other than BLE beacons? WIFI's accuracy is too low.
    - janekm 9y ago
      There are very promising "ultrawideband" solutions (allowing distance to be determined from time of flight of a message rather than signal strength) but the use cases are limited as there is no existing infrastructure. The best that can be done on phones is "sensor fusion" from all available sensors (including wifi and BLE, also integration of motion data) but it requires very extensive mapping of the location in advance. iOS suppports this since a few releases ago but only for locations that have been mapped by Apple so the use cases are rather limited, presumably the mall/airport feature just shown used it.
sriram_iyengar 9y ago
We were working on a travel card TOP up problem using mobile phone and it required NFC parity on iOS and android.
DINKDINK 9y ago
iPhone support for a NFC 2FA key would be powerful.
bschwindHN 9y ago
The only thing I use it for is checking the balance on my suica card (train pass) on Android, but iOS already has a suica app.
baobrain 9y ago
I have yet to meet someone else that does this, but I use nfc tags to shut off my alarm in the mornings. It forces me to get out of bed to shut off my alarm. Not very exciting but indispensable to me.
FroshKiller 9y ago
I have an NFC tag on my keychain. When I'm out and want to remember my location--where exactly we parked, where I saw a neat building--I use Tasker to write my GPS location to my keychain. I could just as easily save a note with my location, I guess, but I like that the NFC tag stores the data without power, without putting it on someone else's computer, and without making it casually discoverable.

MikeKusold 9y ago

The Yubikey NEO is the only NFC device that ever got me excited. It'd be nice to be able to store all my TOTP tokens on the device instead of the phone. Also, signing/encrypting text with PGP from the yubikey.

hdhzy 9y ago
Sadly there is no NFC token that supports 4096 bit RSA keys (I'm not even talking about EC keys). Fidesmo also has support for PGP/U2F over NFC.
- brians 9y ago
  That's okay. RSA-4096 is suitable for long term secrets, but we're talking about authentication: typically signing short challenges, or DH key shares, for immediate verification. The requirements for that application are much lighter.
  - hdhzy 9y ago
    How do you authenticate through NFC PGP on Android? Is that something specific to your company or is there a public app that you're using?
    - xorcist 9y ago
      You can use something called Openkeychain on Android. It uses NFC Yubikeys for both PGP and SSH. Regarding your 4096 bit requirements, normally when you have those security requirements you would keep that key offline and use shorter lived 2048 bit keys for actual authentication. There is 4096 bit support with Yubikey 4 which unfortunately isn't offered with NFC.
      - hdhzy 9y ago
        > You can use something called Openkeychain on Android. It uses NFC Yubikeys for both PGP and SSH. Okay, but open-keychain does not provide GUI to just sign or authenticate a user (you can sign as part of encryption process) so I was wondering if the parent was mentioning some application that interfaces with open Keychain (like k9mail or conversations.im) that gives just that: user authentication.
      - hdhzy 9y ago
        > There is 4096 bit support with Yubikey 4 which unfortunately isn't offered with NFC. Yes, but OTG adapters work pretty well here or one can use Yubikey 4C if the phone has USB-C input.
potatolicious 9y ago
Absolutely this. SMS 2FA has security flaws that are becoming ever more evident - U2F via NFC is a great way to authenticate on Android, and I'm looking forward to having it on iOS as well. Edit: Welp. Looking at the U2F NFC spec it looks like some exchange with the key needs to occur, so without transmit access we're boned.
- hdhzy 9y ago
  > U2F via NFC is a great way to authenticate on Android Unfortunately as far as I know only Yubikey NEO and Fidesmo card support it with Fidesmo being practically not usable. From https://www.fidesmo.com/nfc-u2f-android/ https://www.fidesmo.com/nfc-u2f-android/ : > Google’s own account security website, that on desktop allows you to register U2F devices, says that the feature is not compatible with the Chrome browser on Android. The account security site on GitHub seems to support the feature is a bit better. When pressing the button to add a token to the account it properly launches Google Authenticator to register the U2F device. When tapping the card and returning to the GitHub site however it doesn’t seem to have registered that anything has happened.

threeseed 9y ago

The biggest use case is probably for public transport. That's something where you are tapping on/off multiple times a day.

givinguflac 9y ago
Thanks for the reply. That does sound interesting and would certainly save a lot of disposable cards/tickets. Here's hoping more interesting uses come about with this increase in user base!
maratc 9y ago
Reading NFC transit passes doesn't sound too exciting. I mean, if a phone has an NFC chip, why not use the phone (plus an app) instead of a transit pass, tapping with your phone where you're expected to tap with your pass? This is like your phone wouldn't come with a music player, but would come with a full-fledged oscillograph instead.
- ben1040 9y ago
  There is this Android app that allows you to read your transit pass to check the balance. It's pretty handy with a Clipper Card, for example. http://codebutler.github.io/farebot/ http://codebutler.github.io/farebot/ That said Chicago seems to have the most convenient system along the lines of what you're talking about -- you can use plain old tap and pay at the terminal with Apple Pay or Android Pay.
  - maratc 9y ago
    Reading balance is not too exciting, as I said. There doesn't seem to be any Android apps to let your phone function as a transit pass. I understand why it would be cool to let your phone replace your transit pass (as it's cool to let your phone replace your credit card), but I don't understand why it's cool to let your phone replace a transit pass reader.
    - cwyers 9y ago

rosser 9y ago

I suspect that the general lack of exciting things involving NFC might have a little bit to do with the fact that ~half the mobile audience couldn't do anything with them. That appears to have changed, so this consequence probably will too.

MBCook 9y ago
I always figured that was a big part of why QR codes didn't take off in the US (irony: Apple just added support in iOS 11). Even so, I'm kind of surprised that NFC hasn't come up with more interesting use cases than easy pairing and as a mode/location switch to mark you're at home/work.
rtpg 9y ago
if you could go beyond reading NFC tags (and also allow apps to use the NFC chip fully), then you remove the need for things like physical loyalty cards (like the Starbucks card). That's a really basic use case, but popular enough in Japan, where even old flip phones had NFC
dilemma 9y ago
You mean 10% of mobile users couldn't use NFC.

russell_h 9y ago

I don't know about a "killer use case", but I use NFC on my Nexus 5X all the time with my Yubikey Neo or to check the balance on my transit pass. I'm surprised iPhones were missing this, its not killer but its definitely useful.

ben1040 9y ago

One nice thing is bluetooth pairing. I bought a pair of Bose QC35 headphones recently. There is an NFC tag embedded in the headphones. I just had to tap my phone to the headphones and hit an "accept" button on my phone, and they were paired. Similarly a friend has a box plugged into their stereo that's essentially just an A2DP receiver with RCA outputs, and has NFC on it for pairing. I wanted to play some music on his stereo at a party, and all I had to do was tap my phone to the receiver and start up Spotify.

MBCook 9y ago
Apple sort of does something like this using BTLE on the 4th gen Apple TV as part of setup. It's kind of nice. But the idea of having it in headphone and routers and printers and other things? I can get behind that. Easy pairing is a use case that makes a ton of sense.
rconti 9y ago
Do you just tap, or do you have to launch an app first? I only ask because the bluetooth pairing process is already pretty painless (I have QC35 and an iPhone).
- pathompong 9y ago
  I have Galaxy S7 and Sony SBH20. It's just a tap and they're paired.
- JohnTHaller 9y ago
  You just tap if you have an Android phone with NFC. I purposely got a Bluetooth speaker with NFC to make pairing easy. Whether my girlfriend or I use it or most of our friends of we go to the park or bring it to a BBQ, it's much easier than the usual manual process required on iPhone.
- rollingpebbles 9y ago
  I have an iPhone 6S, QC35 and a MBP 13 mid-2012. The Mac won't stay paired after booting and sleeping once. Only fixed by rebooting (kext reloading, process killing, bluetooth debug menu don't work). Also, it's annoying that it won't charge and stay powered-on simultaneously. Finally, there's ground loop noise originating from the iPhone if charging the iPhone & QC35 from the same source with using the audio cable together. ProTip: Apparently, the QC25 remote cable with buttons works on the QC35 too.

matthewcford 9y ago

Reading your blood sugar levels - https://www.freestylelibre.co.uk/libre/ https://www.freestylelibre.co.uk/libre/

stormbrew 9y ago

I think the thing is that uses of NFC tags aren't and shouldn't really be expected to be individually mind blowing. It's just something that can, in aggregate, make your life more pleasant by small increments that add up. Being able to read my balance on my clipper card with my android phone is something I miss since switching to ios. A promising thing I once used was wifi network ssid/password settings stored on an nfc tag on a wall (think restaurant). But, really, if there's a killer app it's probably payment and it's rolling out. Pretending that it's somehow distinct from other NFC use cases is pretty silly. It's just one of the most obvious ways it can be useful.

brad0 9y ago

I worked on some prototypes years ago on android that handled a payment from a contactless bank card on your phone. So in the payments space: - phone as a payment terminal - peer to peer payments I'm sure there's more than that but they're the low hanging fruit

MBCook 9y ago
Unfortunately it's read only so that stuff won't be coming to iOS.
- brad0 9y ago
  I don't believe you need to write to the card in order to do payments. You send byte streams and it generates OTPs.
  - MBCook 9y ago
    I was thinking of cases where you may need to update the balance on the card. You're right, if you only used it as authorization I guess you wouldn't need write access.

jseliger 9y ago

Most modern cameras have, for the last couple years, used NFC to quickly and easily transmit photos from the camera to the phone. From what I understand, on Android this works pretty effectively. On iOS, however, weak NFC implementation means that one must use a kind of janky WiFi transfer system. It works, but it's kind of difficult to use and not very elegant.

brad0 9y ago
Are you sure it's transmitting over NFC? I thought NFC is quite a limited bandwidth connection. Maybe it's creating the initial connection over NFC and doing the actual transfer over wifi?
- jseliger 9y ago
  Good point; you're probably right and I'm probably wrong, since I'm recalling seeing videos that demonstrate how NFC works w/ cameras on Android versus iOS. I do have an iPhone, so to get pictures from a camera I have to (usually) manually select the camera network, then go to the app, then start downloading. The clunky software camera companies ship doesn't help, of course. If I were in charge of a camera company I'd publish an API and SDK and welcome the world's many hackers to make the camera better, but alas I'm not and no one asks my opinion.
- hengheng 9y ago
  NFC is used to transmit the login credentials, which is fairly nifty actually.
- izacus 9y ago
  Android has a protocol called Android Beam where NFC is used to negotiate transfer which is then moved to either Bluetooth or WiFi Direct. That's probably what cameras are using. Between phones you tap them together while a picture / video is open (which is admittedly less elegant than AirDrop... although significantly more reliable in my experience).

zik 9y ago

In Australia most over the counter payments are done with NFC cards. Some banks allow this to be done with a wave of your phone so you don't need to carry credit cards at all.

Andrenid 9y ago
I just switched to this a week ago and loving it. I can go for walks and carry nothing but my phone, and still grab a coffee etc. My last week of spending has been done entirely via NFC payments.

adambrenecki 9y ago

Don't forget, it's not just about consumer applications. Anywhere you might use a QR code or traditional barcode, but you don't want to have to worry about the barcode becoming obscured or worn with use. I know we've thought about using them to track vehicles and some kinds of parts in the automotive retail company I work for, and there's probably plenty of other industrial applications for them.

giobox 9y ago

It reminds me of the ridiculous excitement over iBeacons when Apple announced their proprietary NFC-like tech a few years ago. Virtually every iOS dev I know bought some cheap iBeacons thinking "wow this is so cool" and never ended up building anything useful. I wasn't immune either, as the abandoned iBeacon in my desk drawer attests to. There's undoubtedly great use cases for NFC on phones (payments, travel passes, hotel room keys etc), but it's also a technology that often seems to attract developers solely because it seems 'cool', not because they have a problem that can be solved better with NFC than without it.

dzhiurgis 9y ago
iBeacon protocol is not proprietory. BLE covers larger area that NFC does not. I agree there aren't much real uses tho. But we might not know yet. For example LoRaWAN networks are deployed worldwide fairly quietly.
abritinthebay 9y ago
Beacons a) aren't Apple exclusive b) are really cool. The trouble is that the category of features they solve can often also be solved by GPS, Network, or other similar technologies. There are a myriad of cool things that Bluetooth Beacons can do but none of them are particularly consumer must-haves.
- wensheng 9y ago
  Might be off-topic, but anyone know what other techs provide indoor distance tacking/localization other than BLE beacons? WIFI's accuracy is too low.
  - janekm 9y ago
    There are very promising "ultrawideband" solutions (allowing distance to be determined from time of flight of a message rather than signal strength) but the use cases are limited as there is no existing infrastructure. The best that can be done on phones is "sensor fusion" from all available sensors (including wifi and BLE, also integration of motion data) but it requires very extensive mapping of the location in advance. iOS suppports this since a few releases ago but only for locations that have been mapped by Apple so the use cases are rather limited, presumably the mall/airport feature just shown used it.

sriram_iyengar 9y ago

We were working on a travel card TOP up problem using mobile phone and it required NFC parity on iOS and android.

DINKDINK 9y ago

iPhone support for a NFC 2FA key would be powerful.

bschwindHN 9y ago

The only thing I use it for is checking the balance on my suica card (train pass) on Android, but iOS already has a suica app.

baobrain 9y ago

I have yet to meet someone else that does this, but I use nfc tags to shut off my alarm in the mornings. It forces me to get out of bed to shut off my alarm. Not very exciting but indispensable to me.

FroshKiller 9y ago

I have an NFC tag on my keychain. When I'm out and want to remember my location--where exactly we parked, where I saw a neat building--I use Tasker to write my GPS location to my keychain. I could just as easily save a note with my location, I guess, but I like that the NFC tag stores the data without power, without putting it on someone else's computer, and without making it casually discoverable.