Wii Remote

The Wii Remote (often called a Wiimote) is a game controller for Nintendo's Wii gaming system. It's a Bluetooth enabled device that contains an accelerometer, a speaker, 2d infrared detector, in addition to the buttons, and d-pad.

This device been taken advantage of by hobbyists and researches to do a myriad of things including an electronic white board, head tracking to enhance 3d effects, and a game controller for games on Android phones.