How can I rotate the screen of a MacBook Pro 90 degrees?

I am running Windows XP on a MacBook and have found while holding the ctrl and option keys together and pressing the cursor move keys (home pgup pgdn end) orients the screen in the direction of the cursor key.

To rotate the screen when reading a PDF or word file, simply hold control and right click the mouse. You can rotate the screen, and your mouse, etc. still runs the same, so you won't get disoriented.

On MBP's with multi-touch, you can rotate content in Preview.app using the 'two finger swirl' ;) or you can use cmd-L or cmd-R. This works in OX 10.5.x, but I don't know about earlier versions.