Okay, you asked! There are others but these are the two I was proudest of. Both of them were hatched at the University I used to work for, but before anyone asks, I quit -- I wasn't fired
(and I still, technically, work for them as a consultant).
Prank #1 "The Cookie Monster"
This one wasn't an original idea. An old joke (I think it originated at MIT), it basically is a little program that sits in the background and periodically, asks
gimme cookie
Naturally, what are you supposed to do? You feed it, by typing in "cookie" of course!, and it goes away for awhile. If you don't, however, it asks again:
gimme cookie
and if you still ignore it, then it prints, over and over,
cookie cookie gimme cookie cookie cookie gimme cookie
and obliterates whatever you're doing on the screen, and then waits again to ask for another cookie. So, I wrote a suite of shell scripts that emulated this, and let them run in the background of the help desk terminal (where support calls are received). The guy at the desk that day was naturally totally unaware and went about his work for a few minutes, until:
(phone rings)
Herman: Hi, this is the {such and such} Help Desk, can I help you? ... Okay, then tell me --
Computer: gimme cookie
Herman: Huh? No, not you, the computer just did something weird. (Over his shoulder) Jordan! {the system administrator}
Computer: gimme cookie
Herman: What? ... No, no, I'm going to have to call you back. ... Sure, no problem. I'll have to ask Jordan why it's --
Computer: cookie cookie gimme cookie cookie cookie gimme cookie cookie cookie gimme cookie cookie cookie gimme cookie cookie ...
Herman: Argh, my screen! It's all messed up! JORDAN!!!
Unfortunately, Jordan had it figured out in two seconds and removed the Cookie Monster from the help desk terminal. There were only a few people in the department capable of this, and only one who would actually do it, so I was found out.
Prank #2 coming.
"you're a doctor.... and 27 years.... so...doctor + 27 years = HATORI SOHMA" - RoyalWing, when I was 27
"Al hail the forum editting Shooby! His vibes are law!" - Osaka-chan
I could still be champ, but I'd feel bad taking it away from one of the younger guys. - George Foreman