Good office pranks I've see/done;
If you use cubicles;
1a. get PS2/USB extenders and switch mice between two computers. So the cable from one goes under from computer A, under the wall and up to the desk of computer B, and repeat. If you're tricky, you can use a repeater/mouse switch so you can control movement of mice from multiple computers.
1b. Install VNC clients on peoples computers. Edit registry so that the tray icon does not show. Then have fun as you make them continuously make interesting typo's.
2. I replaced the foam filling in a cheap office chair with candy corn. The chair was on it's last legs, and I got preauthorization to defile office equipment.
3. I didn't physically do this, but a friend was out of town for April 1st, and he had an actual office (with walls, door, and all. The dimentions were approximately 10x10, so not a big one. We had our contstruction crew come in and do a QnD remodeling job. We turn his office into 4x5 office. Large enough for the door to open, and have room for a cardboard box with his phone on it.
4. I made a lifesize hamsterwheel out of PVC, took a bunch of hoolahoops, and colored cellophane wrap and made a kind of human habitrail for the VP of IT (I was one of his lowly Peons at the time). We tried to get enough shredded newspaper to cover his office, but it was large.
5. Same office, but turned it into a bordello. Large heart shapped bed, in place of desk (made from cardboard boxes}, covered with cheap red fabric, red lights, and Barry White on the stereo.
I can't think of any others ATM, but there are more.
