Here's how to use your iSight camera as a *full-screen* mirror.
This is a follow-up to a previous hint about using Photo Booth as a mirror.
If you select the File » New Movie Recording menu item in Quicktime 10, you get a window of your iSight camera that can be made full screen. Photo Booth has always been constrained to a small window.
[crarko adds: Yes, it works. I hear Carly Simon singing in the background while testing this.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20101124093405705