Write about any pranks that you have pulled at your work. have fun!
Old company. EDU and ADMIN networks. Setting a file, email and cron server up with mouse-disabling, "trap error" (CPU hang/lockup) screensavers then while out in the field realising in horror the Sys Admin we set up failed to try the keyboard and was bouncing the servers manually (switching them off at the button) since they do look locked up!!!
The fact the drives lights were whirring away and no alerts had gone off also slipped his perception in his panic to get them "going again".
I think the last joke was on us with that one actually, but boy was it a hoot anyway
Current company, our boss at the time had a PDA that goes "whiish" when he plugs it in, and "whoosh" when he unplugs it. Now, it plays "1-2-3-4. Hi-5! 1-2-3-4-Hi5. Hiiiiiiiiiiii-Five!". During a documentation project for that same boss, I was at my desk all day long and I set up a sound at startup that said loudly "Good morning! And welcome to another day chained to this machine". Drove him nuts!
I once shifted a users entire desktop icon set into a single folder, locked access to the folder to admin rights then named the folder something she would recognise who did it. She called me absolutely livid, I unlocked it there and then.
And not so much a prank, but once I was working in a tyre fitters shop, 3 of us young guns with nothing to do and the manager chatting when a hottie came in needing 2 front 13" tyres and quickly. Boss joked "you came to the right place then".
Cut a long story short as she decided on which tyres to buy, one of the guys went up the stock racks above the machines where we were poised to compete and show off! We did it in blistering pace and with one extra hand moving into position the tyres were replaced, balanced and bolted back on and me handing her the keys thanking her for her time in all of 4 minutes.
It took about the same time for her to believe it enough to actually walk out with us and look, she only thought we were just yanking her chain!!