**UPDATE** Here is the original, form back in 2009. So sorry we missed it!
Great looking robot that will cut a cake into as many pieces as you want. A tin lid acts as the cutter, and some basic math is used to calculate the angle of each piece.
As others have commented, all it needs now is a way to blow out the candles :)
via MAKE : http://blog.makezine.com/archive/2011/08/mindstorms-cake-cutting-robot.html