One thing that drives me crazy...
I work as a librarian at a largish county public library. Frequently, a customer comes up to my desk, gets my attention, and starts to ask for help (finding a book, signing up to use the computer, etc.). Suddenly, in the middle of the conversation, they get a cell phone call. They hold a finger up to me (indicating "just a minute) and then start talking on their cell phone.
It's especially a pain because I can't really concentrate on the other work I'm doing while they're standing at my desk, but I don't have enough information from them yet to start the book search... I do my absolute best to make my displeasure known by tapping my fingers on the desk or giving them impatient looks. My favorite is, after giving them a minute in case they just want to tell the person that they're at the library and will call them right back, then I just continue our conversation where we left off, as if I haven't noticed that they're on the cell phone. Usually that will make them stalk off to the lobby to have their conversation... and good riddance!
