LiquidMac

The movement sensors included in MacBooks are pretty handy, and if you don't think so, just ask the developer of LiquidMac. Here you have a program that's capable of creating a particle system that reacts to the computer's position.

For now, it seems like it only reacts to the movement of the computer from side to side. The particles will move left or right depending on the movement of the computer.

That said, LiquidMac lets you change an important number of characteristics of the depiction, including the gravity imposed on the particles, the color, rigidness, etc.

In short, LiquidMac is a very interesting tool for testing your computer's motion sensors.