Lock Computer Mac OS X – Updated
There are a couple of ways to make your Mac require a password when you leave it. The easiest way is to set “Require password after sleep or screen saver begins” in the Security section of System Preferences. Here, you can also set a time limit so a password isn’t required right away, but only after 15 minutes for example.
If you would prefer a keyboard shortcut to lock the screen, you can create this yourself. Open up Automator (in the Applications folder) and choose a Service template. From the library choose “Run Shell Script” and drag it across to the workflow area. In the text box paste the following command:
‘/System/Library/CoreServices/Menu Extras/User.menu/Contents/Resources/CGSession’ -suspend
Finally, change the “text” drop-down menu above the workflow to “no input” and then save you workflow as “Lock Screen”. To add the keyboard shortcut, go to the Keyboard section of System Preferences and click the Keyboard shortcuts tab. Select Services from the list on the left, then scroll down to the bottom of the list on the right to find “Lock Screen”. Double-click on the area to the right “Lock Screen”, then press the keyboard shortcut you want. I used Command-Control-L.