Until this year, I have not allowed students to use their phones during class. I had several reasons for this: texting, looking up answers, using the camera, etc. However, at the start of this year I decided if they would soon have iPads, they would be able to do many of the same things. I think a good change would be to allow students access to their phones when they need to look up a definition, Google or research a topic, or when they didn't get all the notes copied off the board and can easily take a picture to use at home, etc.
Although I had always had the rule no phones, I think this change will make things more convenient for both my students and myself. Why should I limit their resources? Instead, I need to work on teaching them how to properly use their device so it is helpful, not a hinder or distraction to their learning.