To all those with external monitors, did you get another webcam? I mean if you use video chat, and want to view the image on the big screen, but your cam is on the macbook... or you're in "clamshell" mode.
Rocketfish 2 MP webcam. The advanced features are disabled in OS X, but it works without any additional drivers (big selling feature) and has amazing automatic brightness control. I can sit in nearly dark conditions, and using only ambient light and the light from my monitor, it's almost as if I had the lights on.
I still have an old Firewire iSight that I use. But if I manage to find an iSight ripped from a recent model MacBook/MacBook Pro for cheap, I would try to jury-rig it to work externally.