One night when you have a few friends around, take turns calling the
same phone number, a really obnoxious acquaintance that won't
recognize your voices is always a good choice.  When the person
answers, try to leave a message for John Smith (or any name that
sounds real). Insist that you have the right number and even read
their number to them. Have a bit of fun here, and stretch this on as
long as possible.  Repeat several times, once or twice an hour. Let
everybody have a turn at calling. Just as the party is breaking up,
call one last time.  Tell the poor soul answering the phone that you
are John Smith, and ask "Are there any messages for me?"  This is sure
to get a groan.