Click--> Income distribution
This is an amazing map of New York City, that provides the percentages of lower, middle, and upper classes in each section of New York.
The only issue I take with it is that many of the sections of the city on the map are too broad. I think many of these sections contain some of the richest and poorest neighborhoods within them. Another problem of course is that neighborhoods like Greenwich Village for example have many people living on very low income, but it is almost impossible to move in to the neighborhood with low funds. Many residents have great rent only because they have been living there for 30 or more years.
Still it is an amazing interactive map and really provides a good starting point into understanding New York City.