I absolutely detest being interrupted while I'm looking at the overhead menu while standing away from the line and counter to order. Someone at the counter invariably calls out asking if they can help me with anything, then saying that if I need anything let them know. Yes, I will let you know if I have any questions and when I'm ready to order, but I'll go to the sign that says 'order here' when I am. Meanwhile I have to start reading the menu all over again to figure out what I want.
This happens at almost every coffeehouse and cafe I go to. It has gotten so bad that I start berating them before they actually do it, distracting myself from looking at the menu. *sighs and shakes head*