Macbook Users - What's Your Screen Usage?

I have recently purchased a 13" Air, and was considering how other users of a similar screened Mac have their screens set up for day to day?

My 'main' set up is the Twitter on the left portion of the screen and a safari window to the right taking up about 80% of the screen. I will occasionally use other Desktops for iTunes or Xcode and the like. So whats your desktop plan? Do you use full screen apps? Multiple desktops? How are you the most productive on your limited screen real estate?