I just bought myself a second-hand AppleTV and wanted to configure it, but I don't have one of those modern flat screen television sets yet (just an old CRT with only a SCART plug), and the Apple TV doesn't come with any kind of cable or adaptor, so I was stuck.
However, somewhere in the back of my mind I found something about sync signal being sent on the green channel of RGB, so I connected the green channel of the component video to my TV, et voilĂ , I had the Apple TV menu (in black and white, but I didn't care) and was able to configure it. This may be obvious to some, but it wasn't to me. My AppleTV is now happily playing my music and movies (obviously also in black and white for the moment). Hope this helps someone.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20071011231658848