I have an Apple Pro Mouse that stopped working. I thought I would tear it apart to see how it worked before I threw it away, at the very least I could salvage the LED from it. As I held it in my hand I realized it was the right size and shape to become a belt buckle. With it's two-layer construction, the design could be custom and interchangeable.
Step 1: Dead mouse
Dead Apple ProMouse. In the background you can see the logitech mouse i found on the sidewalk that made a great replacement.