Lovers of Windows customization are sure to like this freeware. BumpTop is a fun, intuitive 3D desktop that keeps you organized and makes you more productive. Like a real desk, but better. BumpTop replaces your desktop with a visual environment unlike any you’ve used. It has a cool futuristic look.
BumpTop 3D Desktop
BumpTop has a variety of standard themes included in your download, which help you to personalize your experience. Beyond that, there are other themes available through affiliated websites. On its website, you can see the many BumpTop themes available for download, and see how your theme can change your desktop capabilities.
Works on Windows 7 & Windows Vista.
You can download BumpTop from its home page at BumpTop.com.
PS: It appears to be no longer available, having been taken over by Google.
You might want to check out this ultimate list of tools, links and guide to customizing Windows 7 instead.