This is the project from Ethan Frier and
This solution to making city cyclists more visible seems to make sense. The complexities of having to create a 360 degree spinning array of RGB LED's looks to have been overcome. The arrays change colour based on whether the bike is cruising or braking and are powered by a generator on the front hub. Not only probably a very effective safety device, but a fashionable one at that. The project is still a work in progress, check the source to see more.