That’s right, Simmunity has created the world’s first tongue-controlled GameBoy Advance SP. This modified console is compatible with most titles, but “games which require multiple simultaneous button closures will require an assistant to help push extra buttons during play.” Here’s how it works:
…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
[via Destructoid – Zipped]