Funny you should say that, one of my most enjoyable moments was in a shop where the girl was clearly talking to her mate on the phone about what her previous night was like. Meanwhile numbnuts here is standing waiting patiently while she prattles on. (im sure I've covered this on here before!). Finally (well, OK about 30 seconds) my patience snaps and I lean over the counter and press down the receiver button to cut off the call. The look of utter shock on her face was class. Some curt advice on customer service was then dispensed.
Of course it was the early learning centre and by now my, at the time, very young kids had went in different directions, just to strip me of that air of snootyness as I collected my stuff in a gruff manner.