Windows XP PC inside an old Nintendo Gameboy
"Some inventive oddbod has successfully fitted a fully functioning Windows XP PC inside an old Nintendo Gameboy. The device can be connected to a monitor via a normal VGA port, while you can browse the Internet using the built-in network connection. What’s more, they’ve added two USB ports and replaced the A and B buttons with LEDs showing power and activity. Windows XP is installed on a Compact Flash card that’s conveniently inserted into the Gameboy’s cart slot."
More information here. (Note: Auto translated by Google)