I made it back from New York in one rather sweaty piece and am subsequently delighted with the Typical British Summer we have been experiencing for the past week! Since most of my time in New York was spent at various libraries I didn't manage nearly as many cultural activities as I would have liked.
I do have a couple of good recommendations, though: on the museum front, the Merchant's House Museum is worth a visit. A preserved 19th century home with recreated interiors and an especially good kitchen - water pump, a full cooking range and a pie-safe (pictured below) - I love all that stuff!
Also the Folk Art Museum was excellent - very varied and interesting. This detail is from an incredible papercut, made by a prisoner in the 1830s.
If you can catch it before 14th September, the Asa Ames sculpture exhibition at the Folk Art is really remarkable too, displaying amazing wooden portrait sculptures (good pictures on their website to give you a feel). Also, if you're in New York, definitely stop at Blossom in Chelsea, an excellent gourmet vegetarian restaurant (or it's sister branch, Cafe Blossom uptown): I took my very carnivorous host and she was impressed!
I stocked up on lots of ideas for the next visit as well - Governor's Island, the Cloisters, Morris Jumel Mansion, the Rockefeller observation deck, Green Wood Cemetery in Brooklyn, the Highline Park (once it's finished) etc etc... Oh, and obviously, many more trips to Moo Shoes (they have live-in cats!) and Purl (where, just as everyone would have you believe, you DO feel like you've died and gone to tasteful-craft heaven). Can't wait to get back with Miles for a proper holiday, maybe 'autumn in New York' next time to avoid the heat, though!