so you've been in new york for a few days now and constantly going out for lunch and dinner is shrinking the wallet. rapidly.
here's my best suggestion:
pack a picnic. and head to the museum of natural history (located at 80th street and central park west). if you want to go in, by all means do...a more exciting museum is difficult to find and while they suggest a price, you are able to pay what you want/can (with the exception of certain exhibits, as well as the imax).
but after a long morning of exploring the innards of one manhattans great treasures, ask for the outdoor terrace (corner of 79th and colombus). and plop yourself down under the shade of some trees (there are tables) and feast on the beauty of the landscape, as well as the good (cheap) food you've brought.
the area was built in the great tradition of european gardens, and you can feel it...it transports you. it feels private and beautiful, is nearly an acre in size, and rests against the glass encasement of the space exhibit.
if you are coming with small children, pack water clothes for them (but know the boys must wear shirts, no matter the age, and everyone must wear shoes--water jellies and crocs come in very handy) and don't forget the spf, of course. then let the kids run free through the fountains.
and if you're feeling the need for a calming moment...walk to area against the glass wall, where all the water drains...feel the buildup on your feet and marvel at how small you are in relation to...everything.
the best news is...it's free. you do not have to visit the museum in order to partake in the splendor of the terrace.
do know that during the winter the terrace becomes a polar rink (a skating rink...but not quite, because it's not ice).
i have to say this is my new favorite place in all of new york. it's a great place to go to feel as though you've gotten out of the city. it is here that i can read, write, have lunch with a friend, and of course... run through the fountains (because i'll never be too old for that).