Being an engineer should be tons of fun when you are one, so why not spread the joy by pulling engineering-style pranks in the computer lab?
1. Flip the screen! If you see someone forget to lock the screen, hit ctrl-alt-arrow key. Holding control-alt and an arrow key (any direction but up) will rotate the screen that way! (it usually only works on older OS, which is perfect for most computer labs.)
2. My desktop doesn't work! Take a screen shot of the desktop (make sure nothing is highlighted and you can't see the mouse!) Paste it into Paint and save it. Move all icons from the desktop into a folder, then set your new background. Everything will look the same, but none of the icons will work!
These are the easiest pranks that involve no downloads and wont do any damage to the system.
To prevent these from happening to you:
ctrl-alt-del to get to the menu prompt, then hit "Lock my Computer". You will just need to enter your password to get back onto the system, and will be safe from pranksters!
*note, this is only for PCs. Sorry Macs!