Sarah D.'s blog about Cell Phones in the classroom made me remember when I was observing and interning in high school math classrooms and the most common excuse for having their cell phone out in class was that they needed the calculator. I always thought it was a kind of tricky way for the kids to try to use their phone in class.
I can see however, that in the future, cell phones, especially ones like the iPhone will be an asset to learning. This does however give the students more chances to cheat on tests (its easier to send other students the answers when they have something like a cell phone available). If a way can be found to limit this availability, then I think cell phones will have a place in the classroom.