My eventual goal is to create an ambient wall piece that I’d have around my apartment as a sort of interactive decoration. I was thinking I’d have it change according to music or vibrations. Well I have some preliminary work done — I have the arduino communicating with a tri-color LED bar, which is powered through an external AC adapter. Currently they change colors by having each individual color (RGB) fade in and out with pulse width modulation. I gotta give thanks to Jesse for an example layout using a zener diode (to protect the arduino) and a darlington transistor array. Next steps will involve buying a microphone and vibration sensor to start toying around with different potential interfaces.