Uzu

Uzu is a kinetic multitouch particle visualizer that lets you create a vortex of color and motion. It is a sort-of math-physics-art-toy for anyone who ever loved spirographs, fireworks, planetariums, lava lamps, light sabres, pen lasers, tesla coils, Christmas lights, or graphing calculators.

The points of light will shoot across the screen and fly to your command, twirling in a vortex of color and motion. Uzu lets you quickly switch between 10 different modes of real-time animation by simply changing the number of touches you're using.