Are you running Windows? Does your dual 24″ screen set up leave you wanting more? Are you jealously glancing over your friends Mac OS X Spaces? Here’s a solution for you (actually, two solutions).
VirtuaWin is a open source application that enables virtual desktops in Windows. It is highly configurable and lightweight. You can configure how many desktops you want, hotkeys, if you want to be able to drag windows across desktops and a bunch of other things.
If you are looking for an alternative to VirtuaWin you could try Destops by the crazy talented dudes Mark Russinovich and Bryce Cogswell. It works similarly to VirtuaWin with one big exception: It actually creates new desktops rather than hiding and showing windows.
I found that Desktops works really well, but it is not as quick and configurable as VirtuaWin. However, creating new destops has its advantages. If you are running an good ol’ XP setup with problems shutting down properly it works really well to create a new desktop and shutting down the computer from that one. Odd, but nice!
You can get Desktops from the Desktops site.