Windows 7 Shortcut : Windows Key + 'L'

Windows 7 shortcut that's less well-known, but extremely valuable, especially in a setting where you need to secure your computer if you're away from it for a few minutes: "Windows" key + "L".

The Windows key is the one with the little flag on it, normally on the lower-left part of the keyboard. Using that key combination immediately locks your desktop; if you've password-protected it, no one can get access to your computer without the password.

You can do the same thing by clicking the Start button, clicking the arrow next to "Shut down" on the menu that pops up and clicking "lock", but this is fewer steps. If you have a screen saver on, your computer will also lock down when the screen saver activates; but this could take several minutes as well.
So remember "Windows key + L" to make your computer safer. Get in the habit of using the combination every time you get up from your computer.