We had a manager who's office was down a long hallway. You could see him coming down the hall to our cubicle area. Since his visits were usually unpleasant, I would wait for him to get about halfway down the hall then dial his extension. He would stop and go back but of course I would hang up just as he was about to enter his office. I would usually repeat this 3 to 5 times and he almost always went for it, sometimes sprinting back to his desk in an effort to catch that call. Of course this was before we had any caller ID and it did make his visits even less appealing. Asking us "whats so funny?" over and over helped. I once rang him into 8 consecutive trips back. Laughing now just picturing him lumbering back to the phone.