This is a really cool map, from the Census Department:
You can see statistics down to the level of the census tract.
A couple things it really helps to visualize are, (1) how segregated we are in so many ways, (2) how much labor force participation correlates with incomes, (3) and, hence, how segregated we are by labor force participation, and (4) how much high incomes are building around Washington, D.C.
I am sure there are many other interesting things to capture from this map. I think Choropleth mode is the best way to look at it.
The income inequality among neighborhoods is really easy to see here. The incomes around the boroughs of NYC are interesting.