This site has the most original computer pranks I have found. Most other computer paranks either require a long setup, and a fairly good knowledge of computers, or they trigger the anti-virus as a warning, because the program actually changes the computers settings (as a virus would).

Acme 2K provides 100% free pranks that are simple to install, after the prank has completed it stops running, and guides you (the person being pranked) to the unistall application, and is easily uninstalled. The anti-virus doesn't alert you because the pranks are flash based animations and do not change any of the computer settings.

One of the cool features of their pranks is they can be timed when to go off. During the installation you are asked when you would like the prank to activate. So if a co-worker is on an hour long lunch break or a 10 minute restroom break, you can time your prank to go off when they get back, and you can also warn the rest of the office to keep an eye on that person at that particular time. This ensures you don't miss the fun.

Acme 2K has a large variety of pranks available and the pranks are small files that can be stored on a usb disk to take with you since you never know when you may need them.

My only complaint is that they haven't added new pranks in a while. I've already got everyone in the office with the old pranks. Please Acme 2k, if you read this, add more.