YES. This would be great. The only problem that would arise is when a person is expecting a very important phone call, like a wife going into labor -- in that case, people don't have the option of being reachable.

The emergency scenario is why I suggested a switch to turn the blocker off.

I understand, but turning the blocker off then allows EVERYONE'S phone to ring during class, and we've seen what happens in a class of 70 people. Further, people might get accustomed to not having to turn off their phones, so that when the blocker isn't on, there might be even more rings. Also, with a class of 70 people, I'd guess that at least once a week someone would need the blocker turned off (think of all the people waiting to hear about job offers who are too anxious to wait for lunch), which defeats the purpose of the blocker. It would be interesting if the blocker could spare individual phones that request cell phone service and have instructor permission, so the rest of the class still doesn't have service. Or better yet would be a device that could still allow service, but would not allow phones to make ring sounds (i.e. switch all phones in the area to the "vibrate" function automatically).

I like this idea. It sounds simple to implement, addresses a widespread need, and in my opinion, its benefits seem to far outweigh its weaknesses. Nice job.

I think this is a great idea that can apply to other scenarios as well- having worked in a theater, even after the "turn your cell phone off" announcement had been made, phones would continue to ring. I wonder if for important "people"- those doctors who might receive emergency calls, husbands with pregnant wives, MBA's with job offers there were a way to override for just one cell phone rather than shut off the whole blocking system.

This idea is already being worked on by theaters, mainly in cooperation with paint companies. I recall reading about a type of paint which successfully blocked cell phone signals, but the theater group decided not to deploy it. Their reasoning? Liability. People have a reasonable expectation to have access to their cell phone in case of emergency. There are some remote scenarios where people trapped in a theater would need to use their cell phones to contact emergency services, reference the Moscow theater hostage crisis of 2002. This type of liability also applies to schools, as any sort of Columbine scenario makes obvious.

Personally, I just bring a toy water gun to the theater and "shoot" people in the backs of their heads when they use their cell phone. Happy movie-going!

Instead of jamming it OFF, why not have the blocker turn every phone in range to be turned to VIBRATE mode? That way, people can still get their potential emergency call and the class is not disrupted.

Also, the blocker could be used to block INTERNET access as well. Some people like to take notes on their laptop, but professors don't like it. Take out the worry and focus on teaching

What happened to the old fashioned way of reaching someone with a possible emergency like a pregnant wife in labor. Babies came long before cell phones were invented. And as for the job offers, it could wait until after class, lunch, etc. , and believe it or not, Doctors used to go to movies without waiting for cell phone calls too.