Except that it drives everyone else nuts
-Carol Haynes
That's a social issue, and those rules change in different places. Still, I don't think that it will prevent anyone from doing using their mobile devices with voice when it is finally "there". People do it now anyways. Let's face it -- nobody cares about anyone else, and being demure or polite is so last millennium. 
-Renegade
I'm with Carol on this one. Social Issue (Meh...) no. Educational issue ... definitely getting warmer.
Lets take two people talking in a crowd. They will typically speak just and only loud enough to be heard by the other person. Now put one of these people on a cell phone.... And suddenly they are seized with the need to inhale deeply so the can bellow into the phone loud enough to be heard in the next god damn county. Why? Because they're to freaking stupid to realize that one of the phones most basic functions is to amplify the speakers voice so it can be heard.
I sometimes get calls from one of these people, and no matter how far
I turn down the volume. I can't make out what they're saying because the (their) phone is distorting so badly from their inanely loud choice of speaking voices.
Or to put it in nice short words: Use you're
indoor voice when on the phone ... it isn't designed to be screamed through, and you're not up in a tree trying to be heard on the other side of a fucking jungle..
This behavior isn't rude ... It's retarded.