Reading that thread reminded me of a prank I heard of at McMaster. Members of a climbing club would rappel down from the top of a four story building and tape Playboy centerfolds over the windows of professors offices and some classrooms. The windows didn't open so It was difficult and time consuming to remove them.

Anybody who has worked backstage at amateur productions has likely seen a whole host of small pranks. two I remember hearing of were putting a turtle under a cocnut shell on stage so that when it was lifted up the turtle started moving. Or getting a comely young woman to dress(?) in a VERY revealing swimsuit just off stage so that the exiting character had to cover his exclamation (JESUS!!) with a pretend sneeze.