bhonda - 10:10 am on Jul 5, 2013 (gmt 0)
While I see the point that is being made, I have to disagree. It should be fine to speak on the phone at a checkout.
Why is the customer there? To interact with the checkout operator or to pay for their goods? I sure do not go to the supermarket to interact with the staff, I go to buy stuff. Can I do that whilst speaking on the phone? Yes. Does that hinder the job of the checkout operator? In most cases, no. They can do their job, which is allowing me to pay for stuff.
Obviously, if they needed to ask me something and I couldn't answer, that's another story. But there is no principle involved here, just necessity.
How about this other situation - what if I and a friend went shopping together, and at the checkout I was engaged in a conversation. Would I have to cease speaking to my friend in order for the checkout operator to do their job? No.
Having been on both sides of the checkout in my time, I don't see this as a problem.
(But, personally, I don't like speaking on the phone when other people are around.)