I know there are banks here in Sweden where you can get one-time VISA numbers for online purchases. You enter a maximum amount where you guess your purchase wil

I know there are banks here in Sweden where you can get one-time VISA numbers for online purchases. You enter a maximum amount where you guess your purchase will end up, you get a VISA number and expiry date and all that, and it's valid for one purchase. If someone stores that number or tries to use it again, they're shit out of luck because the thing isn't connected to your account, you are not liable in any way. However, those are only practical for occasional purchases, I'd assume you would run through the numberspace pretty quickly if everyone had that by default on their cards. But it's a neat idea. :-)