Following is a list of pranks you can pull on your boss. Just remember to say "April Fool's" at the end so you don't get fired. Now run in to your bosses office and say...
"I real admire your ethics. What do I need to do to be like you?"
"Spearmint Rhino is on the phone. They wondered if you still want to leave your tab open since it's already been three days." [Note: This doesn't always work, as sometimes it's true.]
"I really like it when you stare at my cleavage. Can you do it some more? And don't forget about my butt. I've been doing the elliptical 30 minutes a day."
"The latte maker at Starbucks is broken."
"You have to give up your iPhone because we signed Kyocera to a multi-year marketing consulting deal."
"They're reassigning coverage and you now only get to work with Lionsgate." (or if your boss is in TV, replace Lionsgate with NBC.)
"You know what? Don't bother hiring me. I'd rather Temp because health insurance and paid vacation seem like too much of a hassle."
"I just saw your wife at lunch with John Mayer." (or Paris Hilton, depending on sexual preference.)
"I just sold my script to Warner Bros without an agent for $600,000 against $1.2 million. Yeah, that's the same one I've been trying to get you to read since 2007."
"Mandatory drug testing starts today."