With some basic techniques, you can look snazzy even on a webcam!
Chris references the Down and Dirty Lighting Kit found in the Learning Center. But in a pinch, you can even settle for the light thrown off by a computer monitor. You can use iGlasses to adjust webcam settings on a Mac -- it's available for $19.95 and there's a free demo to try. There's also a Windows version.
How do you make sure you look your best on a webcam?