Yeah, you could certainly just buy a plain USB flash drive and install Knoppix or whatever on your own, but that never stops companies from commercializing what you can DIY. FingerGear is offering a Linux-based Computer-On-a-stick USB 2.0 Flash drive sporting a complete bootable operating system out of the box. It's running Linux 2.6.x with a Gnome GUI, and comes in capacities from 256MB up to 8GB. It also comes with OpenOffice and a bunch of other common desktop and internet utilities pre-installed (GAIM, Firefox, etc.). These are starting at $149 for the 256MB version.