Flip 3D allows you to browse among your active windows via a 3D environment. Introduced in Windows Vista, it is also present in Windows 7!
Using the Keyboard shortcut
Under Windows Vista, an icon allowing you to navigate through Flip 3D, was present in the taskbar. In Windows 7, this icon has disappeared . But as Windows Vista, there is a keyboard shortcut can be used use
Windows Key+ Tab
You navigate by pressing Windows Key or using with the mouse wheel.