Heh, only pranks I tend to pull are the "Got a secret for you, turn over this card." thing, where the other side of the card says the same thing. Or making a "Bertie Bott's" style bag of jellybeans and letting people try their luck. I do warn them that there are nasty flavors in that little pouch, of course.

And, of course, an oldie but a goodie, miniature whoopee cushions slipped into a coworker's chair. I reserve THAT one for April 1st pranks only.