if you have a tv tuner card that accepts a video source..
you can hook up any old camcorder as the video source, get the appropriate WDM drivers (drivers.com), and your off to the races!
i've got an old Hi-8 camcorder running off a ATI TV Wonder VE card and messenger 6.2..the video is WAY better than any web cam (i have three of those as well, logitech, intel, 3com)..plus you get better optics, zoom, autofocus, and better low light sensitivity.