IMO the worst is on the bus, people yakking away at twice the volume of a normal conversation. In a restaurant you can call the manager over and say, "either you tell that person to quit right now, or we're leaving." Faced with loss of business, I think that the restaurant will do the right thing.

Jammers have to be used with the same discretion as a cellphone: you only do it when the conversation being held is non-emergent. Since everyone knows what the person is talking about anyway, as we're all within earshot, that should be a relatively easy thing to deduce.

Plus that, you don't have to have the jammer working all the time--you can jam one conversation (say about meatball recipies) and again when the person tries to redial--but you don't have to keep jamming continuously. Just until the offender leaves the area.

I'm all for jamming. I read an article that said that the FCC has never imposed the $10,000 fine that comes with being caught and convicted of cellphone jamming.