I think that movie theaters, libraries, places of worship, etc. should able to install jammers.
Also, classes. There is a girl who sits next to me in one of my classes and talks on her cell phone during lectures almost every day. I swear, if I was a professor, I would say before class every time "Please turn off your cells now," and if I caught a phone ringing or a person talking they would be dropped from the class. Honestly, you have a person who spent eight+ years training and learning sharing their wisdom with you, and you have the audacity to talk on your cell to your boyfriend during a lecture? This is exactly why I hate cellphones.[/quote] As a professor committed to treating students like adults, I do think your classmate has the right to remain ignorant. But I wouldn't tolerate the way she disrupts class and imposes ignorance on others. I'd just give my lecture from right behind her (or, barring that, from as close as possible). If your professor can't move from the front of the room how about some social pressure? A little staring by people around her or a few comments should do the trick. Polite confrontation can be a great tactic. Shame can work wonders. Of course, for those who don't respond to polite confrontation, the jammer does sound appealing.