When checking out at a store and the cashier is talking to another employee the whole time. I used to be a retail manager and I always told the cashiers that the person at the register is the whole reason they are there, pay attention to them. On a similar note, the person on the phone at the cash register srives me nuts. The cashier is trying to communicate with you so that you can get on with your self centered little life. Hang up the danged phone so you can get out of the way of the rest of us.