"The Chicago Department of Aviation (CDA) and HMSHost are pleased to
announce the grand opening of the O’Hare Urban Garden, a cutting-edge,
environmentally friendly aeroponic garden located in the mezzanine level of Terminal 3, G Concourse." - O'Hare News Release
My sister and I were lucky to have had the chance to be flying through O'Hare after they just opened the aeroponic garden to the public.  They are currently harvesting lettuce, herbs, peppers, and edible flowers, which are then used in providing fresh dishes for patrons of airport restaurants.  Hopefully this will be replicated across other travel hubs.