How can I launch screensaver with a keyboard shortcut?
I don't believe there is a built-in, system wide Keyboard Shortcut. The quickest way to activating the screensaver via the keyboard is either via a "Start Screensaver" command using a launching applications such as Quicksilver, Alfred, or Launchbar.

The quickest way of starting the screensaver using your mouse is via Hot Corners. Open System Preferences, click "Desktop &amp; Screen Saver", click over to the "Screen Saver" tab and click the "Hot Corners" button in the bottom left. There you can specify a corner to roll over in order to start the screensaver.

If you want to start the screensaver quickly, because you want an easy way to lock your computer, a possible answer is located in the high-view "Mac OS X Hidden Features Tips &amp; Tricks" question that remains active.

And specifically, this answer.


  shift + control + eject    send display only to sleep (great for locking your computer instantly)