You know all those annoying people who talk into their cell phones as if you weren't standing right next to them? It turns out that many of them aren't really talking to anybody. The New York Times recently described research at Rutgers University as well as the Ethics and Public Policy Center that found that a great number of cell phone users are faking it.
A number of people make fake phone calls on their cell phones just for the benefit of those around them...
The only way to deal with this is to fight faking with faking. When you're waiting to get off a plane and the guy next to you makes that "We're just pulling into the gate, and I'll call you from the baggage" call, you can top it with "This is the last time I fly commercial. I'll meet you at the helicopter."
When that obnoxious businessman shouts into his phone, declaring he's about to make a fortune because he was clever enough to buy Amalgamated Apple Sauce at 12, you can always talk into yours and say, "What's that? Amalgamated Apple Sauce is down to 3½? Well, at least I sold in time."