Audio Surf

Theres a game I saw recently called audio surf. Its basically a game where you collect colored boxes to gain points. There are a few variations though, like lining 3 of the same colors in a row, or make color clusters to get points.
The interesting thing about it is that the course is created by the music you give it. Depending on the tempo and beats, you get climbs or drops. Its strange, but the graphics do look rather spiffy though.
There was demo version on their website.