Lock screen via keyboard on Mac OS X

I want to easily lock the screen on Mac OS X, preferably without using the mouse or having to install any other utilities. Assuming the security setting requiring a password to wake from sleep or screensaver is set, here is what I have found:

• Control-Eject key sequence will bring up the Restart, Sleep, Shutdown dialog window. Press s to put the computer to sleep. From comments on The Design of the Mac OS X Shutdown Feature via Keyboard shortcut of the day.


• Add /System/Library/Frameworks/Screensaver.framework/Versions/A/Resources/ScreenSaverEngine.app to the Dock (via Quickly lock your screen). Unfortunately Spotlight doesn't seem to find this app, however the keyboard shortcut to open the Dock is Control-F3 and typing sc selects the ScreenSaverEngine.

Update: Command-Alt-Eject will put the mac to sleep. Thanks to Kristian.