Audiosurf on Steam. This is great.

[Feek]

You load a tune from your music library and then play a custom made tetris sort of game with a little car driving along a track collecting coloured blocks.

Sounds rubbish.

It's not!

Six quid on Steam, this is an absolute steal.

Review (http://www.eurogamer.net/article.php?article_id=93012) - Read it, download the demo, play it, buy it, play it lots :D

[Dymetrie]

Already installed the demo and will have a go at it later.

Although I find it unlikely that I'll be racing to the sounds of Floyd :p

[Garp]

I bought a copy of it.. not sure about it to be honest. Haven't really got into it. It does work better with dance music, and electronica.