I searched through the threads a while ago as well looking for a solution. It seems I wasn't alone in finding there really doesn't seem to be a good solution to this problem. As far as hardware goes, the best multiple input video source comes from the CCTV industry. These are specifically security cameras and their corresponding hardware. Unfortunately, the video quality is very poor, as well as their seemingly non-existent compatibility with mac platforms. I also did some searching through companies like Black Magic etc, they quickly replied that they don't make units that capture from more than one source at a time.

My next thought was to go to webcams, however, after doing some research there, it seems like the USB bus can only really handle one high quality webcam at a time. So adding more cameras is not really possible, unless you have multiplie USB busses. I don't like that answer and don't think it's right, but it's what I've been told multiple times now. Anyways, just thought I would add to the post, if anyone has a good solution, I'd love to hear it as well.

-Colin