Last year I originally bought a Logitech Webcam Pro 9000 to chat with my mate who moved to Austrailia, thinking an expensive webcam would be good. When chatting to him, even when he was in the UK, he would say that the picture always froze and would be like that until we ended the video conversation. Being annoyed about this and wanting a camera that actually showed me moving and also with my voice properly synchronised, I decided to buy a cheap webcam, and as my friend had a Philips and his appeared to be working well, I went for this model in Comet, no frills (no manual focus or face tracking) and was cheaper there than on here.
I am absolutely bowled over with this, it is superb, no freeze frame, voice is always synchronised correctly and picture quality is great, even in low light conditions. As I said no frills, but you don't need that for normal webcam chatting. It also has a seperate mic, with a resonable length cable, so you can position it near you, or stick it on your monitor or laptop. I can complain for £14.99 at Comet.
PS. It does have a snapshot button on the side of the camera and it can be difficult to hold it steady and shoot a picture. You can solve this by downloading AVACAM a freeware program, which has snapshot functionality at the click of a mouse button.