I had my xbox 360 controller connected to my pc and I noticed some wierd symbols that looked similar to the xbox 360 controller buttons, then i joined a game i realized i can use my controller to play!! There are not enough buttons on the controller to bind things to so there are some things like shooting that you cant do with the gamepad! Just try it its pretty cool. Here is a video i found about it [media]http://www.youtube.com/watch?v=ntm8odruJ20[/media]
You can do this with most games just download a copy a xpadder and it lets you bind your xbox buttons to buttons on your keyboard i did it with a old mmo a while ago. http://www.youtube.com/watch?v=i1WuGaHNTcw