Open House New York. Too late for the tours that you need to register for in advance but there are plenty of spaces and places to explore.

http://thestarryeye.typepad.com/explorenyc/2012/08/open-house-new-york-call-for-volunteers-2012.html

I will post again later today or tomorrow about my planned itinerary. On Sunday, in between my Public Theater tour and Brooklyn distillery tour I will probably be exploring the open studios in the Brooklyn Navy yard.

There are dozens of smaller museums and indoor activites - from the Frick to the NY Historical Society to the main branch of the Library or a tour of Grand Central Station. (Check out the Campbell Apartment - which is an upscale cocktail lounge up on a mezzanine with great views. Also consider dining in the Oyster Bar on a lower level.)

Also suggest you check out the website of New York magazine, which has an events section with hundreds of listings - by date and type. And Time Out New York site has info on musical events all over the city.

My advice: Make reservations now for brunch on Sunday morning at Robert, atop the Museum of Art and Design on Columb Circle. Call and see if you can get a wondow table as it has an incredible view of the corner of Central Park. Food is good, and there is a piano player. It is lovely, even in the rain.

I just checked and they have spots available on Sunday a.m.

http://robertnyc.com/

On Sat. when it isn't raining: Have you ever done a walking tour of Central park? It should be nice this time of year. We did that on our last trip and loved it, walked ahnd in hand a lot of theway...so many things to discover and so much history we weren't aware of.

For drinks, have you thought of going to one of the "speakeasies" in NYC? We have been to 2nd floor on Clinton (that's the name of the place) and it was intriguing, romantic, and cozy, and the drinks, while pricey, were great and unusual. We loved it.

http://www.2ndflooronclinton.com/

There are so many great romantic restaurants in NYC. Where are you staying?

Not sure if you'll enjoy this but we did. Burlesque in Tribeca:
http://www.duaneparknyc.com/

Special Events: You might want to check out "Discovering Columbus" - an artist built a house around the top of the statue, so you can essentially hang out with Columbus in his living room. I haven't been yet, but my friends loved it.

http://www.publicartfund.org/view/exhibitions/5495_discovering_columbus

While there, check out the Time Warner Center - right behind the statute (Columbus Circle). Not for the glitzy shopping, but for the spectacular views on second floor and higher. Not sure what your budget is: there are bars, restaurants, a few clubs (Dizzy's Jazz) with dazzling Central Park backdrop. And it's right next to the Museum of Art and Design, suggested above.

Enjoy!

Thanks for all your suggestions everyone! I appreciate it!

Oh an d the weirdest part of Central Park that we didn't expect was the roller skating disco dancing area. It was beyond unexpected. We spent an hr. watching grannies and buff guys doing disco dance moves on skates, w/a DJ and disco music.

The Royalton Hotel, on West 44th, has a great lobby bar; very cozy and atmospheric. The gas fireplaces are always going, it's dark and sexy all day. The martinis are served very cold. Love it.