When travelling with kids in New York, definitely go to the American Museum of Natural History -- specifically the Hall of Ocean Life. The room is cavernous and absorbs all screaming toddler noise, and there are benches for tired parents. Can easily run off a lot of young kid energy for a couple hours. The restaurant/cafeteria is also not bad and has some edible and not-junk-food selections. Older kids will love the adjoining planetarium. The space shows are pricey but worth it (for kids age 5+).