Competing with MotionX from Fullpower is Mach Dice, another application for your iPhone that realistically simulates dice rolling.

You can select different dice with various numbers of faces. I don’t know if you can select a die that wouldn’t roll fair in the real world, such as a d13, but it would be cool if you could, and there’s no reaon why you shouldn’t be able to.

Anyhow, one cool thing about Mach Dice is that if you tilt the iPhone, the top down view of the dice tilts with you, giving a full 3D effect.