I travel all the time and use services like Airbnb, and many many others to both meet people and find more interesting places to stay. I live in Kips bay which is close to a lot of great neighborhoods, and can offer advice for restaurants and places to go out for pretty much all of Manhattan.
My travel philosophy is to locate myself where I can have the maximum impact and see the most in the shortest time. However, unlike itinerant travelers like Clark Griswold of the Vacation movies, I don't think it's important to rush to all the sites in the guidebooks, but rather to work smarter to combine experiences. I like to leave projects, shopping or even errands that I would normally do at home for other countries, and I like taking or teaching classes while traveling as well. When it's absolutely necessary to hit the tourist spots (and I do feel the need to do that) I try to experience them from the angle of a local - like finding the best rooftop bar to view the empire state building from rather than queueing to go up in it.
I'm also an iPhone and iPad nut so I can help you configure your phone with all the right apps to make the most out of NYC - NYC is much better with all the social services switched on and humming.
May your travels be interesting...