The little-used Hide Finder command (Cmd+H) in Mac OS X can prove invaluable when you have a ton of Finder windows open and don't want to have to close all of them manually. Choosing Hide Finder makes the Finder inactive (another currently running program becomes active) and hides any open Finder windows. To make the Finder visible again, either choose Show all from the Finder menu (or whatever it's called in the active application — the command should still be there) or click the Finder icon in the Dock. The advantage to hiding the Finder — rather than closing or minimizing all your windows — is that you don't have to reopen all the windows.