Balls is a highly addictive (for me, at least) little flash app whose sole purpose is to grab you and hold you and force you to keep reducing the balls until the 4 big balls you start with become 4 to the 7th balls, or 65,536 balls.
It’s a wonderful lesson in the power of, well, powers. After many hours (many hours), I have completed this task. The image below of the completed board might help save you from the same obsession.
H/T to BoingBoingfor pointing to this one a while back.