i got half life 2 on my laptop few nights ago and i was wondering if i could somehow use my ps3 controller to play instead of the keys and mouse. this possible at all?

I'm pretty sure this is possible. My friends been playing L4D on the PC with his PS3 controller and as L4D are both made by valve and distributed by steam these a pretty high chance you can. Unfortnatly as i do not own a PS3 i do not have any first hand expirence of this. I just noticed that the steam Half Life 2 page says "Controller enabled".