With the Nintendo Controller Synth, you can make music with your video game controller. This custom synthesizer was built by Michael Rucci out of an old NES controller.
The A and B buttons make some funky sounds when pressed, sound which can be distorted and tuned by the knob over the D-pad. Fans of electronic music should dig this, and even non-fans like myself can appreciate the time and effort it takes to turn a controller into a serviceable music maker.
Be sure to check out the video to hear the Nintendo Controller Synth in action.