Best tech pranks

[montyrule]

Mine is that i unplugged the power switch (for the front panel header) on my IT teachers computer! 

 

List yours below!

[Excon]

That's not a prank, that's just being a dick.

[Tea1337]

I told me friend he could download more ram and HDD space. and that he could also download a better GPU to be able to play battlefield. Then I Installed a fake virus onto my sisters computer and watched he freak out for about 40 minutes.

[JAKEBAB]

mute the headset and let my friend keep talking like people can hear him.

[Advent]

Putting a fake BSOD screensaver and disabling wake on mouse movement on all 250 computers at my high school for April Fools day. (NOTE: I installed and maintained ALL 250 computer and continued to do so for 4 years w/o any kind of pay or compensation). That was probably my best.

Or just before graduation we edited the ticker that was around the front billboard to say stuff like "Killroy was here. AYBABTU. HackThePlanet, as well as a whole bunch of Simpson jokes". (Our Principals last name was Skener).

But as far as pranks go:

Inverting mouse movements.
Flipping the screen (will also invert mouse movements).
Swapping keyboard inputs (QWERTY-> DVORAK and vice versa).
Turning up my old boss's (who was a dick and NO ONE liked him, he also owed me 3 months back pay before I was "laid off" and refused to pay it) volume to max and having their windows logon sound a porn clip.
In cubicles, move mouse/keyboard inputs to adjacent cube and vice versa. So they control someone elses computer.
Using NET SEND command to send creepy messages to people in the library (like, I can see you, I know you are in the library, you are wearing x, y, z, you are x, y, z w/ x color hair etc etc etc).
Remotely shutting down/restart computers in the Library.

[Giggitygoebbels]

Open up a keyboard,and stapled the membranes of F8 together.

[beebskadoo]

I print screened my moms Desktop and set it as the wallpaper. I then hid all of the icons/task bar. She couldn't figure it out

[Advent]

I print screened my moms Desktop and set it as the wallpaper. I then hid all of the icons/task bar. She couldn't figure it out

Old, but gold. Done that as the screensaver and disabled wake on mouse.

[Str_Mape]

Wireless mouse at a LAN party when you've got a nano receiver and they have a hidden front I/O panel.

[beebskadoo]

Old, but gold. Done that as the screensaver and disabled wake on mouse.

that's just pure evil

[old reece frost]

I puu.sh'd a youtube page and left the image on my screen, so my sister thought my computer crashed

[Flyguygamer]

I have done a few of the ones above but any others?

[thirdworldking]

we have old computers at school and not all of them have bios passwords so i disabled all but one usb port so they could only use either the mouse or the keyboard and then i put a password on the bios.

[TymmVonD]

Look up .vbs pranks. Those still get me rollin' everytime.

[cjeffcoatjr]

My old math teacher who still thinks that one tab on IE will give you the fastest performance, asked me what the 'compact disc inserter' was called. I said graphics card. Well, needless to say, that turned into a very interesting conversation between her and the IT guy about how "her graphics card wont give her back her compact disc'. 

[Syraz]

Ctrl+Alt+ Down Arrow on other peoples computers and leave it for them to discover

[mgsstar]

Changing the startup sound to some screaming sound and cranking the volume up (saw this prank in a video).