Imagine the following scenario: You can't connect with VNC to your iMac/Mac Mini that runs Mac OS X Snow Leopard. The Screen Sharing service is not enabled. Anyway Remote Login (ssh) is available. What can you do?
Well, you can just start the Service via ssh with:
$ sudo touch /private/etc/ScreenSharing.launchd
Another way I which I did not check is to execute this statement:
$ echo -n enabled > /Library/Preferences/com.apple.ScreenSharing.launchd
Wow, that sime! Now you can connect to your machine via VNC and work with the mouse. ;-) I hope this helps you like it helped me a lot. ■