If you frequently run multiple programs simultaneously or have multiple windows opened side by side, your desktop can get extremely cluttered & looks untidy. This can get annoying if you're working on one program and want to minimize all the other windows except the one which you are working on.
In previous versions of Windows you had to minimize them individually, but with Windows 7's "shake" feature, though, you can minimize every window except the one in which you're currently working in a single step.
* Click and hold the title bar of the window you want to keep on the desktop
* While still holding the title bar, shake it quickly back and forth until all of the other windows minimize to the task-bar.
* Then to make them return, shake the title bar again.
You can accomplish the same thing by pressing the Windows key+Home key combination although doing this is not nearly as much fun as "Shaking".