iPod laser pointer
If you thought there wasn’t anything else to shove on the end of your iPod, [Alex] is here to set you straight. He used the DC power that’s available on the iPod’s dock to drive a cheap laser pointer. It’s pretty easy to do - just get a dock connector (sparkfun has em) and add a laser pointer module. If you’d rather access everything else, check out the super dock I put together a while back. Hit the read link if you’d rather see the picture in color.
via http://www.hackaday.com/2008/03/09/ipod-laser-pointer/