I did that to one of my friends. The message was, "Hey Steve, I'm testing out my new answering machine, so go ahead and leave me a message." His message was something like, "What? ... How'd you know I was going to call. ... Um... Oh, I'm going to be in town..." Totally caught him off guard.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris