Not all airports are limiting the food trucks to the cellphone lots.
Sometime this year or next, Terminal 4 (American Airlines) at Los Angeles International will be getting an L.A. Gourmet Street Truck structure built to look like a food truck. "The concept and façade will change every three to four months, with cuisine from the most popular food trucks in Los Angeles rotating so that travelers get to experience it," said LAX spokeswoman Katherine Alvarado.
At San Francisco International Airport, three food trucks park outside Terminal 1 each Thursday, drawing customers not only from passengers and their greeters, but from airport employees as well.
After a positive reaction to a four-week trial period, the airport extended the food truck service indefinitely. "This program is primarily a response to airport employee suggestions, so the airport only collects a nominal fee of $300 per month for this operation," said SFO spokesman Doug Yakel.
Service plazas: Beefed-up cellphone lots
At the end of this week, the Indianapolis International Airport plans to open a service plaza with a Circle K convenience store and 24-hour fueling station offering car washing, automobile detailing and quick-lube services. Next month, the first of two restaurants will open on the site.
"This arrangement provides a new land lease for the airport authority and, after three years, a percentage of gross sales," said airport spokesman Carlo Bertolini. "It will generate a new source of non-airline revenue, which is a critical piece of our strategy."
And on Sept. 24, Denver International Airport will open a 269-space cellphone lot called Final Approach. It will provide free Wi-Fi, a children's play area, indoor seating and restrooms, flight info boards and four restaurants, including a 24-hour drive-thru Dunkin' Donuts.
"Our customers asked for enhanced service, and we are delivering," said Kim Day, Denver International Airport's manager of aviation.
(Read more: Greener terminal lands at San Diego airport)
The cost of the approximately $5.5 million facility at DEN was paid for by the site operator, Pacific Convenience & Fuels, and airport officials said that in addition to generating more than 100 jobs, Final Approach is expected to generate $2.3 million in gross sales and more than $421,000 in revenue for the airport in its first year.
—By Harriet Baskas, Special to CNBC. She is the author of seven books, including "Hidden Treasures: What Museums Can't or Won't Show You," and the Stuck at the Airport blog. Follow her on Twitter at @hbaskas.