
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 taskbar. Then let go. To make them return, shake the title bar again.
You can accomplish the same thing by pressing the Window key-Home key combination -- although doing that is not nearly as much fun.