In my school, cell phones are banned in classrooms; when you bring one to school, you have to take it to the office and get them to put it in the school safe. Its the same with iPods, MP3, cameras, hand-held game systems, and just about anything else electronic and portable. There was even a stage where Yu Gi Oh cards were banned (that was just ridiculous, since the teachers didn't enforce it anyway). If a teacher sees any of the above, they will be confiscated until the end of the day. Second offence, it goes to the office safe overnight, and third, it stays with the principal until your parent comes for it. And they're allowed to do it too, since a condition of enrollment is that phones aren't allowed.

Its so we don't get distracted. It actually makes sense in my school though, since there are lots of kids here with behavioural problems and learning difficulties.