Ok, so I finally figured out how to rotate your internal (laptop or iMac) display in Snow Leopard. It seems to be a bug (Actually, more like debug code that was left in ), and as far as I can tell it does *not* work under leopard, but so far I've tested this under 10.6.1 and 10.6.2 on my MBP and it works great! I don't have SL installed on my mini 9 at the moment, so if someone could test that'd be great! (Feedback for any GMA950 machines would be much appreciated!)
Here's how to do it:
1) If System Preferences is open, quit it.
2) Open System Preferences.
3) Hold down Command and Option at the same time and click on "Displays"
(NOTE! This must done on the *first* time you open the displays preference pane after opening system preferences or it wont work. If you've already opened Display prefrences without holding cmd and option, quit and try again)
4) That's it! You should now see a buggy looking "Rotation" option off to the edge of the window. Clicking brings up your options for rotation and actually works!
Screenshot attached for reference: