is there a site that keeps track of current filming and the locations where they are happening? i'll be in NYC soon and thought it would be cool to see the process first-hand.

It's rare that high budget films would be filmed out in the open where hundreds of passer bys can easily see. If a film were to be made in the city, it would be in a building, or an empty part of town. I do remember though, when I went to the city one time, Adam Sandler and Jack Nicholson were in a building I passed by filming Anger Managment. This was just before the summer. But search google for ways to become an extra for a film filmed in the city that week/month/however long your there. That's the only way you'll really get a good look at the filmmaking process.

Me: "what's going on over there?"
Answer: "Making a movie called Vanilla Sky"

So I look a litle closer, and yup, there's Tom Cruise.

It happens a lot in NYC.

You might want to search on the web - there is a NYC Commission on Film, and they may have some information anout permits being issued, etc.