Flying used to be an adventure. Now it's an endurance contest. Passengers may be quietly rebelling--in a passive aggressive way--to show the airlines exactly how they feel about those long security lines, overbooked flights, lost luggage and interminable waits on the tarmac.

Wall Street Journal reporter Scott McCartney delved into the underside of airline travel and found more than chewed gum stuck to the bottom of the seat. His No. 1 piece of advice is this: Be very careful as you reach into the seatback pocket, especially if you're in the middle seat. It turns out that we are stuffing those pockets full of trash--from toenail clippings to leftover meals and used diapers to melting chocolate bars. Since the flight attendants, who only do a light clean-up between flights, don't see this nauseating trash carefully hidden in the depths of those seatback pockets, they're left for the next unwary passenger to find.

The middle seat is the worst, according to the Journal, for two reasons. One, kids often occupy this seat and tend to think of that pocket as their personal wastebasket. Two, if the seat is unoccupied, passengers on either side will stuff their trash into it.

Other examples of bad mile-high behavior include passengers plucking their eyebrows, polishing their nails and even blowing their nose into the airline blanket that gets folded up for the next passenger to use. They kick off their shoes and prop their bare feet on the bulkhead or seat.

"Increasingly, passengers are certain that the airlines are not on their side and actually don't care anything about them," Irwin Sarason, a University of Washington psychologist who has studied passenger behavior, told Journal reporter Scott McCartney. "In that kind of environment, it isn't too surprising that people will not exercise the restraints they normally would."

Frequent traveler Patrick Kerr told the Journal that the worst thing he ever saw was a man who chewed tobacco on a flight from Reno to Dallas, spitting the juice into a plastic cup. Just before he deplaned, he tucked that cup of spit into the seat pocket and refused to remove it when Kerr called him on it. (Kerr notified the flight attendant.)