I bring a cooler... always a few peanutbutter type sandwiches on whole wheat, some protein bars, yogurts, fruit, brown rice with some sort of meat and veggie for the first day. If I know the hotels we're going to have mini-fridges, I'll bring even more perishable stuff. Tuna packets are awesome. Oh, spicy beef jerky and some sort of nut mix (Planter's Men's Health Mix is my favorite right now). Keeps me going for long legs or quick turns.

Even when I make the big bucks some day and either upgrade or get a better job, I'll still pack. I'd rather spend my money on stuff at home than airport food. That or maybe I'll take whatever I would have spent on airport food every trip and put it towards my kids' college funds...