There are so many it's tough to pick....one of the ones they always bring up at parties is this: Me and another technician worked in a huge shop/garage building prototype transmissions plus installing them and whatnot at a corperate design and research plant
I was sitting in our office that has a large window overlooking the car lifts and co-worker was standing in front of one of the big tool boxes with a drawer open playing xylophone with the rows of open end wrenches.......I pick up the phone thinking I was going to make him laugh by yelling at him over the shop intercom, but I had never used it before ....when I go to hit the intercom button on the phone, I accidentally hit the "emergency" button and say "Matt, please stop playing with yourself ,Matt, please stop..." and I hung up because I could hear it come thru my phone too?
I look out at him and he mouths "you idiot!" at me, it turns out the emergency button makes every phone go into speakerphone mode and even breaks into peoples conversations that are currently talking on the phone, so say....my german head of engineering who was talking to a buyer at Ford at the time got to hear my advice to Matt.
I hid in the office closet just as engineers began to pour out laughing looking for me.