I always bring my phone 😛 they are allowed if they dont see or here them. I bring my MP3 on some days when have a certain day, because the teacher allows us to use them.
When I had my phone, I took it all the time and would usually text during classes. The rules state no phones at all, so we're pretty sneaky.
Some kids press their luck too far and get 'em taken away. Good thing is, some teachers are very lenient on it, and will give you several warnings, but never take it.