A heads-up for those heading to Dallas-Fort Worth International Airport tomorrow: You'll be greeted by picketing American Airlines flight attendants. The Association of Professional Flight Attendants, which reps the some 20,000 AA employees, yesterday announced it has chosen four airports for its Friday fun: DFW, Los Angeles International, New York's LaGuardia and Miami International. The protest comes almost one month to the day after a New York Times writer flew from Dallas to New York with an American Airlines flight attendant crew in order to answer the question: "Is there a less-enviable, more-stressful occupation these days than that of a flight attendant?" Probably. Can't name one at the moment. Give me a second. --Robert Wilonsky