5. Original GameBoy Mouse
4. GameBoy Advance LEGO RobotCharmed Labs introduces the Xport 2.0, a homebrew application for the Nintendo GameBoy Advance that plugs into the cartridge slot. Practical applications include robot competitions, custom sensor development, and force reflection/haptics.
...allows the Xport hardware to be tailored to your target application, and the 64 digital I/O signals provide programmable I/O for interfacing to practically any hardware device.[Source]
3. GameBoy Pocket ATAPI CD PlayerIf you've got an old GameBoy laying around, why not interface it to play CDs using an ATAPI CD-ROM drive from a computer.
Here's what you need to build your own: A GameBoy (show track information), GameBoy cartridge, ATAPI drive, and a 12V power supply[Source]
2. "Game Man" - World's Largest GameBoy
1. Tongue-Controlled GameBoy Advance SP
...we added a new jack for the receiver input. This receiver processes signals from the tongue-touch keypad and, in this case, relays them to a second micro-controller computer chip inside the Game Boy, added by Simmunity, to decode the reciever signals and activate the Game Boy Advance SP buttons[Source]