The 600 Abacus watch was designed by Roy Schafer and is made by the Erich Lacher Watch Factory in Germany. "The ball moves to and fro across the face of the watch with the flow of the wearer's arm movements, but as soon as the Abacus reaches a horizontal position, the ball moves as if by magic - or at least by magnetism - to the right point in time." This sucker will set you back $152.91 if you're interested. I really like the concept, but it needs a roulette wheel background. I was thinking just the other day that my watch was missing something, and now I know. Balls. I mean watches and balls were practically invented for each other.
Product Site [thanks to the always on time Trisha for the tip]