I've been flying US Airways a lot lately and have learned the fine art of patronizing airport food concessions in that airline's hubs.  If I connect via CLT, I get a Pizza Hut Personal Pan Pizza and drink and bring it on board with me.  If I connect in PHL, I get a 12-pack of Chick-fil-A nuggets, waffle fries and a drink.  In doing so I'm usually the envy of my seatmates.  One added bonus is that these food items don't have much of an odor - I always find it annoying when someone piles onto the plane with some food item that completely overpowers 10 rows of the airplane.