I consider Dexpot to be one of the only viable virtual desktop applications available on Windows because it’s constantly being improved and has many of the features you look for in a program like this. They are also taking some ideas from Mac OS X Spaces with the latest Dexgrid plugin that is included in Dexpot 1.5.10, but is disabled by default.
All this plugin really does is add a grid-style switching UI that you see in the screenshot above, and the animation it performs is exactly the same as Spaces on the Mac. Things like this are nice, but it is really the tight integration into Windows 7 that makes it as useful as it is. Not only do they take advantage of Jump Lists when you right-click on the icon in the Taskbar, but you can just hover over the icon to have it show thumbnails of all your virtual desktops. If you hover over any of the thumbnails you’ll notice that Peek will kick in and you’ll see a larger preview.
If you feel overwhelmed with all the windows on your screen I’d highly recommend trying to organize them into virtual desktops using Dexpot. It’s free for personal use, and it has a lot of configuration settings available so that you can customize it the way you want.
Dexpot Homepage (Windows only; Freeware)