I started this project because I could not find a high-resolution map of income for the US. The map above (with a larger version linked below) shows the median income for every US Census block group in the contiguous US. Each block group contains about 1000 people. As far as I know, this is the highest granularity map of income across the US on the internet.
Many cities have a pattern where the center is relatively poor, but there is a ring of wealthier block groups (presumably suburbs) at a radius of about 10 miles. The goal of this ongoing project is to measure income as a function of distance from the center of a city.