I have a friend and co-worker who just loves to play mean-spirited practical jokes on his friends. Really, really bad ones. The kind where the victim never, ever laughs.
Well, one day, I had a chance to get him back - big time!
He was going away on vacation, and he happened to bring all his luggage into the office before he left for the airport (he was afraid of getting anything stolen from his car). Big mistake!
When he went out for a late lunch, I had a chance to break into his office and go through his baggage. And, that's when I found his laptop computer...
Now, if you've ever taken a laptop onto a plane, you'll know that the security guards will make you take it out and turn it on for them. If the computer turns on OK and they see Windows running, they know it's not a bomb (apparently, terrorists are too stupid to put a bomb in a working computer).
So, I quickly wrote a new autoexec.bat file (this is the file that tells your computer what to do when it's turned on - ie. open windows, run anti-virus, etc...). But, instead of the usual start-up routine, I programmed the computer to just spit out a few images I created in Photoshop...