April Fool's Day - Post Your Best Prank

I work at a college in Daytona and our maintenance dept. has a very work-dedicated secretary. Sometimes she can be rather "difficult". So the general maint. dept. crew (7 guys) called in sick or called in personal leave due to "unexpected circumstances".
She fell for it and needless to say, wasn't happy. She had already forwarded all of our calls up the chain of command. I just happen to walk in to my immediate boss' supervisor's office while he was listening to them - He said, "Hey! That's you!" I said "Yea, it's April Fool's!."
Unexpectedly we got him too, but he thought it was hilarious and a good one.