LOCKING THEM OUT OF THEIR OWN MACHINE

Annoyance Factor 5: This is a good one to pull on someone who is a single user (they're not sharing their machine with other users); thus they're not used to logging in each day with a user name. Go under the System Preferences in the Apple menu, click on the Desktop & Screen Saver icon, click on the Screen Saver tab, and slide the Start Screen Saver slider to, say, 3 minutes. Now (this is the key to the whole thing), click on the Show All button, go to the Security preference pane and check the box next to Require Password to Wake This Computer from Sleep or Screen Saver. Now, every time their computer sits idle for 3 minutes, it will require them to enter their user passwordif they can even remember what it is. Ahh, it's the simple things in life.