i had an old radio that broke, i took it apart and cut off the section that held 3 AA battaries, salvaged the metal thingys. soldered the + to a wire and the - to another wire. Used 3 AA battaries to power a 4.5V blue LED. worked like a charm. So i wiered another LED to it, made a plexi houseing for it. Sence there is a threded hole on the area that holds the batteries im gonna use a flat screw to hold the top in place.
well heres a pic of it so far.
http://home.comcast.net/~mattbradford/coaster.JPG