There was an amazing demonstration of the XBox approximately a year ago where Gates started with an image of a roomful of moustraps and pingpong balls. He ran the demo, which of course results in multiple traps slamming shut as balls are careening about, then he ran the same demo using a different ball to set it off, which resulted in a completely different cascade, all in real time. Its quite an amazing system, and I hope the developers are putting such power to use for something beyond the now-tired formats of first-person shooters and/or racing games.