I recently installed a fully-functional copy of Ubuntu 6.10 on a 4gb Micro Drive. It worked exactly like a standard hard drive, but I can carry it with me and boot into my Linux desktop wherever I may be as long as I have a computer with a fairly recent BIOS that supports booting to a USB device.

I'll work on a Windows version next. I bought three of them at $30 each, shipped. If you want one, you might want to hurry, I'm not sure how long they will be on clearance.