What really gets me is the people who walk away from their phone in a captive environment and don't turn the ringer off. People do that where I work several times a day. If I have to hear 50 Cent phone rings from my cube, for an hour straight, one more time I'm going to steal the phone and call threats into the Oval Office with it.
Sadly, it's upper managers who seem to do it most, since they consider themselves to freakin important that your comfort is not only irrelevant but a stupid concept.
Even this doesn't help much, really. When my wife and I were in the theater this weekend there was like 8 people in there. This guy comes in and sits directly behind us, leans forward half the movie, and is clearly having respiratory problems. I didn't look back but from the breathing sounds I assumed it was an old man with oxygen so there was really no need to be pissed, just uncomfortable. When the movie is over, I turn around, no, it's a perverted looking obese guy who is breathing so poorly he's gurgling on his own fat. 500 empty seats in there and he is breathing on us for two hours. I probably have a disease now.