The mind molester- It is a very small electronic device that chirps or beeps loudly but to short of duration and the noise is spaced to far apart to ever be able to find it. Hide it well and they will never find it.
-cover everything with stickers, those packs of shiny kids ones at walmart. -get a vga splitter and hook it up to the break room tv or whatever so everyone sees what he does. -if he has a file cabinet, remove all the stuff in there, seal up all holes, and fill it with concrete. Luckily Home Depot has a 25% off sale on all Quikrete until tomorrow I think. You could line the hole drawer so it can be removed.
It's called an annoy-a-tron and its the best revenge ever: http://www.thinkgeek.com/gadgets/electronic/8c52/
Yup, I did that for April Fools last year... It was giggletastic. I have to second the "jerk store" though. You can't go wrong with the jerk store.
Switch the M and N keys on his keyboard. Most people will never notice the difference, and he'll sit there and misspell everything for hours not knowing why. I used to intern at a home building company, and one of the guys there had a load of gravel delivered to his boss's front yard. The boss had to call a dump truck to his house to get the gravel out of his driveway, so he could come to work. Pretty damn funny. At the same company, before I was there, one of the guys had his boss's office door sheet rocked and plastered over during the weekend. When the boss came in on Monday, he walked to where he thought his office was, but it was just smooth wall. So he walks over to the next office, and sees that it's not his. So then he goes back down the hall, and goes to the office before his, and sees that that's also not his. Finally, he begs someone to tell him what's going on, and they let him in on the joke. It sounds like it was pure hilarity.
In case you're wondering what it looked like... Doesn't look like much, but it took me a good 30 minutes to clean it all off. Currently, my plan is to go in tomorrow (I've already confirmed that his office was left unlocked). I'm going to be completely wrapping his office furniture and most of his office in our left over yarns. I've also already signed him up to get newsletters from the Log Cabin Republicans.
