I've just upgraded my son's Mac Mini to 10.5, and turned on the Screen Sharing and ssh server after the initial install. In 10.4, I had long ago configured the "hidden" ARD VNC server, though alas I now find I've forgotten the password I set at that time. My son's gone to bed, but I want to play on his Mac -- what to do?
It seems that the "new" screen sharing feature is basically the same as 10.4's, and the VNC password is in the same place: /Library » Preferences » com.apple.VNCSettings.txt. The password is obfuscated by XORing it with a fixed key, so you need a little perl magic to view / set it.
[robg adds: Read on for the how-to. Please note that this isn't a security concern, as it assumes you've got ssh access to the machine in question, as well as the ability to execute root privileges on that meachine -- and if you've got both of those things, well, you've pretty much got the machine anyway.]
To show the current password, do this:
To set a new password (the obfuscated version is echoed back, in addition to being written to the VNCSettings file): Of course, hello is a very poor password, and is only an example here!Mac OS X Hints
http://hints.macworld.com/article.php?story=20071103011608872