Shortcut key to lock screen on MBP/OSX

In Windows, the ctrl-alt-delete key combo will lock the screen. I was surprised that OSX didn't have any key combination to do something similar. I guess Apple expected that people will only want to use a mouse...? Anyway, I find myself wanting to be able to quickly lock my screen when I move away so this is how I did it:

Create an run-only script with the Script Editor with the following:

tell application "ScreenSaverEngine"
activate
end tell

Set an Quicksilver trigger to run this script and map the shortcut key to what you like (I used ctrl-command-delete).

If you have set the screen saver to require a password, you now have an keyboard short cut to locking your screen.