Melanie,
"But again, you refer to the phones in question as learning tools. No one is saying that they're against using phones as learning tools...I think, and I repeat, some teachers are bothered by students who are using these technologies for personal reasons in the classroom..."
It seams to me that you consider "phone as a learning tool" and "proper use of phones" as two separate issues that are tackled separately.
I'd say that these issues are inseparable and by choosing not too use phones in class you are just ignoring the "proper use" part. Just by banning phones you loose the opportunity to actually influence the way students use them. Yes, using phones for personal reasons in classroom (or in other situations) can be irritating, but by curing the symptom (banning the use) you are not treating the cause.
Siobhan:
It seems to me that plenty of people teach under the presumption that attending a class is always beneficial. I don't really know how Ms. Austen or you teach, but most people hold lectures and I don't think those are always beneficial. From experience of most of classes i attended (I'm a student of physics and computer science education in Croatia) if I felt that the lectures were useless and skipped them, but did the rest of the work, the quality of my knowledge wasn't worse than of those people that sticked to the lectures.
And plenty of research in the field of physics education confirms it. Lectures are either useless, or are even bad for the student - after a course that was mostly lectures students behave less like experts (coherent knowledge base, good problem solving skills, critical thinking etc.) than they did before they took the course.
My suggestion would be to allow for different kinds of attendance (not just sitting in a class) and getting the grade (usually there is only one set of activities possible). And in the case of e-mailers one kind of a solution is to build a community (or use an existing one) that can give answers. What we are doing right here is a good example.