I scored a great belt the other day & upon further inspection I noticed that there was quite a bit of space behind the cast belt buckle for a project...
Step 1: Create an Uber Throwie
I went down to my local Rat Shack and picked up some parts to make a blinking LED Light. As luck would have it, they had an LED w/ blinking feature ready-to-go out-of-the-box. The LED runs 12VDC @ 20mA. I decided to step up a notch on the battery from what you would normally see on an LED throwie (like a watch battery.) I found a nice remote control battery that produces 12V and it will give me much longer life than a watch battery.
Next you test out which side of the LED is + & - by touching the leads to the battery. I soldered one side onto the battery and have a piece of tape on the other end to act as the switch. I also used a bit of tape to fasten the LED onto the battery for stability.
Follow that up with some double-stick foam and you are ready to mount the light into your buckle.
Step 2: Mount the Light
Here is a picture of the mounted light. It looks great in the dark. A movie can be seen at:http://220.127.116.11/movies/BlinkyBeltBuckle.MOV
This can be done with lots of belt buckles. Check out Hot Topic for a variety of neat ones.