At last I've found what looks like a fun and decent toy that I need to play with. That being AZ-Tech's ePass2000 USB SmartCard. It's basically all your crypto on a USB stick, which would make it pretty easy to use PKI. Pop in your USB stick, type in your password, and no more passwords! And you could have encrypted and signed communications on any computer without compromising your private key.

This is going to be added to my MUST have list.