Office Jokes

So working in an office, I thought of a couple things that would be funny to do to another co-worker, ok so there is only one for right now...
So my first thing that I thought would be hilarious is to take a picture of someone's screen with the "Prt Scrn" function, and then go into "my computer" and "hide desktop items", and then put the picture you just took as the background picture. Ah ya, I am busting up just thinking about it. This way, they could see the start menu, and all of the desktop icon's but it would be a picture so they wouldn't be able to click on anything... Well I thought it was hilarious anyway.