I've had a couple of goes at the trial version of DeskSpace recently, but each different version had an issue or two that stopped me from using it full-time. Today I finally purchased it because v1.5.4 seems to have resolved the issues I was having :)
DeskSpace is a pretty slick app for desktop management in Windows and works great on Windows Vista. The rotating cube animation for transitioning between desktops is super smooth on my new notebook, and although you can use up to 6 desktops (1 for each side of the cube) I have been perfectly happy just using 2 desktops, as per the screenshot below. I find it works well to do general browsing and other tasks on the first desktop (which I've set to use Win+Q shortcut), and all my coding and testing on the second desktop (which I've set to use Win+W shortcut). Having different desktop backgrounds also helps you quickly recognise which desktop you are working on. You can also drag windows between the desktops if you wish.
At USD$19.95 it's a bargain price and comes with a 30 day money back guarantee too. I'll see how it goes over the next few weeks, but I think it will be sticking around on my notebook for a while!