A Linux distro that fits on a thumb drive

I've been looking for a Linux distro that will fit on a thumb drive. I had no luck, but now a blogger named Jeremy Wagstaff has put together a directory of programs designed for usb drives that points to at least one. It's a 50M disto I've never heard of before called Puppy. Another product they have is called Flash Puppy for booting off a flash card.

Too bad I don't have a Windows box around the house for testing.