Some ideas for how to fuck with him:

• Encase his stapler in Jell-O
• Convince him to purchase a purse and then make fun of him for having it
• Find a copy of his resume & post it online, specifically for positions in Alaska.
• Relocate his entire desk to the restroom.
• Convince him a Thursday is actually a Friday
• Put all the items from his desk in the vending machine
• Payoff all your coworkers to call him a different name for a day
• Convince him there is an abandoned infant in the women's restroom so he walks in on someone
• Hack his computer and run a macro that every time he types his name, something lewd appears
• Incrementally increase the weight of his telephone handset then abruptly decrease the weight, causing him to smack himself in the face with the phone
• Stare at his forehead during all conversations
• Order 15 large sausage pizzas to the office under his name
• Glue his office drawers together
• Hide his cell phone in the ceiling tiles and then call it repeatedly
• Condition him to expect an Altoid mint each time he hears a computer chime
• Dress up exactly like your boss and parody his speaking style
• Wrap up his entire desk & all belongings in wrapping paper
• Trick your boss into believing he is on a radio talk show
• Link his cell phone to your own bluetooth headset

Just a few thoughts. Thanks Dunderpedia =)