If you find your desktop gets overwhelmed by too many open windows there are a number of solutions, from the extravagent like investing in a second monitor, to applications that try to give you an expanded workspace, like the spaces feature of Apple's OSX Leopard.
Madotate is a free English language version of a Japanese developed tool that adds a fourth button to the top right of your windows. Alongside close, full-screen and minimize appears a 3D button. Clicking it will transform your window into a tabbed 3D image, which takes up much less room.
The app was designed for Windows 2000/WP, but also seems to run fine in Vista. The only problem we found was with Adobe Air programs - they don't crash or slow down, but don't transform properly. This was developed before Adobe Air, and unfortunately hasn't been updated since. The 3D effect is quite cool, but if you've played with Deskspace it seems pretty basic in comparison, although Madotate has the advantage of being free.
Matodate is a resource friendly way to add a space saving 3D effect to your windows.