Black Dog
This is very interesting. Drop by a friend's house or a library and instead of messing around with windows, just plug in a little USB stick, that is actually a Linux Powerpc computer running Debian. It uses autorun to run a windows binary that includes an X server and network interception and from then on out the machine is taken over and all programs run on the Black Dog machine.
No worries about keystoke loggers (except in hardware), or data leaking into the browser history, or anything. ssh. X. offlineimap. Drool.
Also includes some kind of biometric (fingerprint?) authentication in case it falls into the wrong hands. I have my doubts that works very well, but whatever.
Anyway, this is a great (and apparently, not entirely unique) idea, and I really hope it catches on and there's lots of competition and these end up on Ebay for $50 (instead of the current $300), and everyone who's stuck using computers at a public library can buy one.
For myself, I'm thinking I can pack three Debian architectures in a square foot for $500 now.