This is a good one for school or business. It's probably been used in movies and TV.

This is a good one for school or business.
It's probably been used in movies and TV.
It was used at this site, to the embarassment
of one of our department heads.

While he was chairing a rather boring department
meeting, the Manager (referred heretofore as Mr. Pid)
Wanted to emphasize a point using the conference room
blackboard.

Several meetings had been recently held in the same
room, and the last had used the pull-down projector
screen, which was now covering much of the blackboard.

With chalk in hand, Mr. Pid gave the screen a little
tug, and released it, sending it straight up and out
of reach.

The entire department almost immediately broke into
uncontrollable laughter.

Mr. Pid was at first surprised, thinking the group to
be amused by the action of the screen.

When he turned around to start writing, we were told
he turned the most lovely shade of beet red, as
taped to the blackboard was a luscious and smiling
Playboy centerfold.

To this day, the identity of the perpetrator is unknown.