Originally Posted by
Ostego
If you have Audiosurf, that means you probably have bought it through Steam. So if you did, then you don't need to purchase it again. Think of Steam as something like MSN. You can use Steam on any computer that has it installed, just like MSN. MSN keeps all your settings, just as Steam keeps your games.
In other words, if you have Steam on another computer, log into your account and play the game. If the computer doesn't have Audiosurf installed, just click install.
Tl;dr
No, you don't need to buy it again.