My math teacher, for example, has everyone put their cellphone on her desk at the beginning of every lesson, not only during tests, and requires that all of them be shut off, so as not to have one of them ringing during class. Oh, and they all have to be aligned and positioned towards her viewing angle, so she can quickly check if they're all turned off.
She keeps a list with every class she teaches at and how many people have cell phones, so she knows if someone didn't put theirs on the desk.
At the beginning of the current school year, she kind of scrapped the list thing, since everyone has a cell phone now. It's been over 3 years since she started doing this.
Parents generally don't complain, and see this as a good move on her part.
It hasn't caused any trouble.
Would this even work in other places? I haven't heard of this kind of thing being done elsewhere, and I don't know why. Would people complain and/or try to sabotage the teacher, so teachers don't risk this? Is it considered more of a risk for something bad happening to people's cellphones? Are there laws banning anything of this sort?