Virtual Desktops (Mac OS X)
 

Very sweet little free app.

http://wsmanager.sourceforge.net/

Even if you think you'll never need more then one desktop the transiton effects are loads of fun to play around with :D

Nice! I am using Fedora Core a lot recently, and I really like the multiple desktop idea (like tabbing but for full desktops). I had asked a friend about such a setup for OS X, but he said the only ones that existed were pretty kludgy. Is this one decent and fast?