Amanda Ghassaei built this fun Arduino-powered noisemaker:
The glitchbox is a sample-based drum machine used for live audio or MIDI sequencing. The buttons on the front of the instrument play back nine audio samples stored in its memory. A switch on top records and loops sequences of these samples. Once a sequence is recorded, additional samples may be layered and automatically looped on top. Recorded sequences may also be temporarily muted or cleared and rerecorded, and two knobs on top of the instrument control volume and tempo.