There's not much to do here in New York City, so we thought we'd give you some ideas...
The Village Halloween Parade
First and foremost, if you plan on spending Sunday night here as well, that will be the date of the 37th annual Village Halloween Parade. I've spent many a Halloween watching and marching in this one... the pinnacle of my involvement being featured with Bryan and lots of friends during our Many Cruise march on the news. You can see it here on YouTube.
Walk Across The Brooklyn Bridge
It's a really nice walk, and a really nice view, topped off with what I hear is some really delicious pizza at the end. Click here for a little guide on how to do it.