Last month we told you about maps of big cities with dots representing races and ethnicites, so you could see how separated or mixed different groups were.

Now The New York Times has improved on that map, offering the ethnic breakdown of “every city, every block” in America.

Here’s Houston.

Keep double-clicking on any particular census tract — say your own neighborhood — and you’ll zoom in to a block-by-block illustration of its demographics. It can be addicting.

This article appears in Dec 9-15, 2010.