How can I use or share the integrated webcam on my laptop as a webcam on my desktop?

I've found the following software solutions, all of them commercial, none of which I have tested, and variability in what OS is supported.

http://www.eltima.com/products/usb-over-ethernet/
http://www.incentivespro.com/usb-redirector.html
http://www.usb-over-network.com/usb-over-network.html
http://www.intellidriver.com/products_1.16.html

Can anyone find a free or open source solution?