Computer Geek Hazing Tactic #02: One funny one I found that works on some Dell computers (maybe others) is to hold down the CTRL and ALT keys at the same time and press the "up arrow" key. This will flip the computer screen display completely upside down.
You can also use the side arrow keys to rotate it either clockwise or counterclockwise. (use the same process with the "down arrow" to put the screen back to normal)
A certain now-marked-for-death colleague of mine (and you know who you are) tested your tactic, Brian. I came back to my desk twice today and found my desktop upside down or sideways. I actually had to do a forum search for "geek hazing" to find out how to set it right again because he left for the day and didn`t fix it before he left. He may not realize it yet, but he`s going down!
Um.... I play the accordion!!! (I`m serious. My dad also played. We`re Polish/Russian.) I guess that`s why my username suits me. 
This thread is GREAT! The only real geek hazing I`ve done is take people`s photos from their web site and attach their head to another body - human or not. Sometimes transvestite. Oh, and once I took an exacto blade to a co-worker`s chair and slid some water-filled plastic bags under the vinyl. It was a chair that was already covered in rips and duct tape. Oh, those were the good days!
My husband has some great tricks that he plays on the other ironworkers (they do rebar placement) that he works with. My favorite is when he slides a piece of tie wire under the victim`s tool belt and up through their pliers so they can`t get them out. I guess a lot of jobs have a hazing of sorts.