> implementations installed by default on every device That's not a trivial ask. Security experts might wonder, "Wait, what new entry point are you mandating o

> implementations installed by default on every device That's not a trivial ask. Security experts might wonder, "Wait, what new entry point are you mandating on my devices? To solve which problem?" They'd caution that several subsets of this problem are already solved, lowering its urgency. You own both devices and have wifi? Dropbox. You have internet access? Email or other messaging services / file lockers. Both devices are the same ecosystem? Bluetooth / AirDrop / WifiDirect / Beam. You are near a gas station or in a house with a junk drawer? $1 USB stick. You didn't forget your cable? Cable. You are both developers? You may already have some arcane solution, depending on the platforms... So, while it'd be nice to ensure two unacquainted technophobes who meet in the woods have the ability to move some file from one's mp3 player to the other's digital camera, despite never having installed any software or brought any drives or cables to help, we're slicing off thinner and thinner portions of salami here. Also consider other approaches. More ubiquitous (functioning) internet solves all of the above, along with several other problems. Absent that, foresight would have prevented a few of the test cases. Foresight isn't trivial, I know, but that opens up other approaches. Like maybe an alarm on a device that rings if the device gets too far away from some other little chip, which you can stick on a cable you want to never forget. A shim to friend and create a temporary shared Dropbox directory with strangers nearby would require advanced installation, but might be useful. I don't mean to diminish the frustration of these situations. If you were talking about developing some software to help local area sharing, I'd say go for it. But putting the bar at mandatory interconnection in all devices... it's a high bar. The mere fact that legacy devices exist makes it impossible to meet those constraints. If you relax your constraints just a little, though, I suspect a few opportunities for interesting work open up.