Kensington sd200V Notebook Docking Station With Video
So in order to transmit a video signal over USB and have it come out the other end on a monitor, you are pretty much guaranteed to need something with DisplayLink, as that's pretty much how it works. Well this docking station possesses such powers, and more.
The docking station also replicates mic, audio out, 4 USB ports, Ethernet, and with the DisplayLink chipset, VGA. The VGA output can be a mirror image, or used to extend you desktop onto another monitor.
The DL-120 DisplayLink hardware that's in this beast allows you to output up to a 1440x900 maximum resolution. So if you have a laptop as your primary computing solution, and you need more than the affixed monitor, and the likely built in VGA out on your laptop can provide, you can get one of these from Kensington. No word on price or availability though.
Kensington USB Video Dock, Powered by DisplayLink & Praised by Workaholics [via everythingUSB]