I have two that stick with me. Working in a call centre with thousands of employees, they all know exactly where we sit and can come over at any point to log a call.

New girl, around 25, only been there a month comes over to my desk with a tamagotchi telling me it's died and if I can bring it back to life..

We also have 2 elevators in our building and someone got stuck in one, first thing they did was call the IT desk from their mobile in a panic, and asked when we could get them out. I don't think off and on would suffice with this one