travelingforever.com - Ditch the Laptop for A USB Key: Travellers "can carry an entire computer's worth of software everywhere they go, and keep a personal mini computer stored on a usb key, accessible through almost any computer in the world."
This posts explains how to set up your USB Key with all the software you need, pretty much all of it free, so that you can have your computer without having to carry around your laptop. I think it's a great idea.