On my PC, I think I hit F4 or F5 and the Microsoft Powerpoint presentation switches from Normal viewing mode to Presentation mode. On my macbook pro (core 2 duo), I have my volume button on F5 and Fn+F5 doesn't seem to do it. Side note: Fn+F6 is very useful. What is the keystroke equivalent to the PC version of switching to full screen/presentation mode??????