Hi there
There are very few IM's which support webcam under Linux. The only one I was able to find is GnomeMeeting, and this works with NetMeeting on Windows (and of course GnomeMeeting :) )
This was my biggest obstacle to switch to Linux on all my boxes, but now I have an old PII with win2000 as my IM-with-video-and-audio-solution (then to discover that VNC is nice, but slowwwwwwww)
The other thing you could try is Palantir (http://www.fastpath.it/products/palantir/index.php), it should be able to stream video from your webcam, not only to web but there is a special client as well. I haven't been able to get it to work yet, but haven't had that much time to look into it.
Sadly things like VMWare doesn't support streaming data devices (yet??) so that's not an option either....
Feel greeted, Angelo