runs through April at the Museum of the City of NY on Fifth Avenue and 104th Street.
I loved it and highly recommend it. There is something vaguely magical and inexplicable in the fact that such a vibrant city grew from the vision of three commissioners who were mostly concerned with merely creating a pragmatic system for selling land and constructing buildings. The simple 1811 Grid became a framework for sustaining not only economic growth but diversity, opportunity, creativity and, yes, liberty. Not bad for three guys who are otherwise pretty obscure (OK, Morris wrote the Preamble, but who knows it?). Go and enjoy this well-designed exhibit and leave yourself time to pore over some of the most engaging maps I have seen (see if you can find where your house/apartment would be amidst the 19th century rocks, hills and trees).