Spoke POV($37-$100) is an electronic kit toy that turns your bicycle wheel into a customized display! Here is picutures. The project includes a free schematic design, open software for uploading and editing stored bitmap images, and a high-quality kit with all the parts necessary to build your own. They are 30 LEDs on each side (22 for BMX) x 256 radial pixels, runs on 2-3 AA batteries for 10 hours.
