On the first day of classes, I make sure that everyone knows that cell phone use during class is NOT going to be allowed. Not a text, not a tune, nothing.
On day two, I backtrack just a bit and introduce them to the county's disaster alert program that residents and students can sign up for with their cell phones.
On Friday, we were using Re:Writing Plus! and logged in for the first time. Except that not everyone was successful. As I walked around helping out the students, one of my students pulled out his cell phone and dialed the 1-800 number for help. At first I was amazed, but then I shrugged and thought that it was an efficient way to deal with the problem.
Today, two of my deaf students were arranging to have other students take notes for them. Instead of relying on the interpreter, they (deaf and hearing) decided to text each other later. During class, one of the students texts the person sitting next to him if he needs something.
I don't have any profound theory or pedagogical move to embed these situations in, except to say that the cell is becoming more and more a part of us that it seems like second nature. And sure, there are students who would text their significant others during class if I let them.