I used LED's (light emitting diodes) on my latest build, and liked them. I got them from an on-line store (I think it was "highintensityleds" or something similar). You have to pay attention to the voltage, watch polarity, and may have to gang some in series or use resisters to make them work. They last longer than grain bulbs, are brighter, and available in several colors. You can buy them from Radio Shack, too, but they cost much more there.