I just finished building the first prototype for a modification to the Black Hole PopBumpers.
I've replaced the bulb with a circuit board and a rotating LED pattern. Drilled out the pop bumper cap; and put it all together.

It's designed to be a bolt-on mod; where you simply remove the existing blub; attach the power bulb, and screw in the circuit board into the existing unused popbumper mounting holes. Runs off of the standard 6.3VAC GI circuit.

I think it looks pretty good:

Click here to view on YouTube.com