In 2009, Bill Rankin created an infographic of the ethnic distribution in Chicago. It was pretty awesome. Awesome enough that a couple of months ago Eric Fischer took the 2000 US Census Data and did the same thing for 40 other cities.
I love Chicago and spent a lot of time there between '04 & '08. It had always struck me with that city that you can walk across the street and literally feel like you are in a completely different place. Just on a level of race, Rankin's work seemed to support that notion.
Two of my other favorite cities in the world are listed below and they tell very different stories. Each dot represents 25 people. Pink is white, green is asian, yellow is hispanic and blue is black.
Austin
Austin is a great city. I haven't spent too much time there, but my girlfriend is from there and I feel like I know it pretty well. The population density is pretty low overall and there seems to be a pretty good mix of ethnic diversity within the various communities.
New York City
Not surprisingly the density of NYC is drastically different than Austin. Although Manhattan at street level has an incredible ethnic mix most of the time, it's hardly surprising that it's so white in terms of residents (except for Chinatown & Harlem).
It's really interesting to see other cities such as Washington, LA, Detroit and SF as well. I've also been watching a lot of The Wire lately, so seeing Baltimore was also pretty interesting.