I personally like keeping my desktop nice and clean, yet functional. This way my desktop wont distract me when I'm running applications like Logic, Final Cut, and Photoshop but still look artistic. I can control my iTunes, my mobile phone, and a few other things all from this simple desktop. And of course i can open Dashboard (similar to Vista sidebar) for more functionality.
This is my Macbook's desktop with Mac OS X Leopard with a few modifications:
Ill post my Ubuntu Desktop sooner or later.