Well suddenly I wanted to know if the Sony miniDV camera could be used with firewire also, and yes no problem it's instantly recognised in Skype.
I also tested the USB connection again on the Sony camera and it's USB1, the Microsoft webcam uses USB2, but the conclusion is that unless you've got ambitions of looking good USB1 is enough.
I expect that most videocameras (DV or Video8) with digital out, USB or more likely DV/i-LINK/FireWire will work with Skype. At least it's worth a try.