By fiddling around with the USB interface of his iXus digital camera, a guy calling himself „uberhax0r“ actually managed to make a whole Linux system run on his device. Check out the photos, it is really cool.
Update: also quite crazy is the project MAMED! which brings the MAME arcade machine emulator and other games (like Doom) to digital cameras running the Digita operating system.
UPDATE: Seems as if I ran into an April Fool‘s joke. The whole Linux on the DigiCam thing is a hoax. I swear I will never recommend anything on the web before checking it :)