I was looking for a simple method to lock my MacBook Air without disconnecting network services and without the usage of a mouse (or trackpack). On MacBookPros or connected external keyboards I can use CTRL+Shift+Eject to turn the monitors of. The MacBook Air does not have an eject key, so there is no way to use it. Now, whenever I leave my Mac, while it is alone in an environment I don't really trust, I can use Spotlight (or Alfred, or Quicksilver or …) to start Sleep Display. It turns the monitor off, and once I return I have to enter my password.
Download the application from github.com and start it with Spotlight whenever the monitor should be turned of. That's it.
Tobias Tom (email@example.com)
You can also clone the project with Git by running:
$ git clone git://github.com/tobiastom/Sleep-Display