Customers who want me to help them but won't get off their freaking cell phones. I had it happen twice the other day when working, that someone on their phone would come up to my window, ask a question, and then when I start to answer hold up a finger like "Just a minute!" and start yapping on their phone. You asked me for help. If you can't get off your damn phone for a minute to let me answer, then get outta my window and come back when you're done. In fact, anyone who's on their phone and needs something, but rather than just getting off the phone and asking tries to do some kind of funky pantomime. This is not charades. If you have a question, need to borrow a pen, whatever, then get off your phone and ask properly.