* 2 USB keys that share a securely generated amount of random data.

* Share one with somebody you'd like to communicate with.

* The two keys can encrypt/decrypt messages to each other using that random data as a one-time-pad. http://en.wikipedia.org/wiki/One-time_pad

* You can then transmit messages across the net in plaintext. You can even tell your partner which part of the pad you are using.

Technically, one-time-pads are impossible to crack. You'd only have to watch out for observation attacks and that sort of thing (perhaps the keys would could be bootable for extra security?).

The keys would only work for a certain amount of time before needing to be "paired" again, their pad data would eventually run out. But with modern keys holding many GB of data, this would take a while.

Obviously this is only for the super-paranoid (or the geeks) who want to chat 100% securely among friends. But hey, 6 months ago only the super-paranoid were using encryption at all and look where we are now.