From Dave Barry's blog today:

Having spent this past week in various phases of air travel, I am wondering if it would be possible to require cell-phone manufacturers to put some kind of decibel governor on cell phones, so that if a person talked too loud into the phone, the phone would stop working. Or, better yet, explode.

I really like the solution proposed in the second comment:

Well, I don't know about exploding phones, but people don't like it if you stand near them and take notes.

Gonna have to try that next time I'm adjacent to a Nextrovert's table.