George Clooney (here in 2007) is a notorious prankster, with pal Brad Pitt often the target. Clooney once convinced paparazzi he was hosting a Pitt-Angelina Jolie wedding on his lawn; another time, he arranged for fans to chant "George! George! George" outside Pitt's hotel room all night. And Pitt once wrote a memo to the crew of "Ocean's Twelve" insisting Clooney always be called "Mr. Ocean" because he wanted to remain in character.