The program LiquidMac is just awesome. It’s a mac program (obviously), and it utilizes the sudden motion sensors in the powerbook and macbook/pro families, to do this really, really cool simulation of…well, I guess it’s some liquid substance. It’s made up of a lot of little dots, which if set to be blurry merge together to make some sort of blue glop, which slides around in its window in accordance to how the computer is tilted. It works amazingly well, and I’ve been playing with it for about an hour. If you have a powerbook, macbook, or macbook pro, you seriously need to try this thing out.