Windowed Gamming

So i got my new macbook and i bought Civ IV today (yay!) and it rocks. I do have a question tho, is there a way to play the game windowed so that i can play it but be able to listen to itunes or talk on IM? or is there a button to switch back to the desktop. THanks for any help.

Apple + M works in WoW

apple + tab? that should work but not sure about fullscreen..
or you could use apple + h