In August, my LAX-NRT was delayed (maybe 2-3 hours). They brought around carts with first class snack basket goodies and sodas in cans and everybody could help themselves. They also had a pop corn machine for the kids, I was really impressed.
I have also sometimes seen soda cans and bags of sun chips offered at the help desks in DTW to delayed pax. A little refreshment can go a long way, especially to the poor kettles that have to stand in those long lines.
Great customer service, Delta! ^