I had been waiting for something to make my camera work. I saw several people post saying that their Firewire Pyro webcams worked in OS X. Well, I went out and got one. And gues what... IT DIDN'T WORK! heh.
Well, I was annoyed, but figured that drivers would eventually come out.
Well, just recently, I saw that something called DCam WebCam driver came out. So, I downloaded it and gave it a shot, and suddenly all the webcam apps are seeing the camera and working..

one Video conferencing app was crashing the chat window when the camera was hooked up tho. Not sure if that is a bug in the driver or the app itself. I'm suspecting it's the app.
http://www.ioxperts.com/prod.html
So, if you have a webcam that hasn't been working, try this. I think it's for Firewire only, tho... not sure.
-Alex