As part of the You Are Here project from the MIT Media Lab, an exploration of independent coffee shops in San Francisco:
Independent coffee shops are positive markers of a living community. They function as social spaces, urban offices, and places to see the world go by. Communities are often formed by having spaces in which people can have casual interactions, and local and walkable coffee shops create those conditions, not only in the coffee shop themselves, but on the sidewalks around them. We use maps to know where these coffee shop communities exist and where, by placing new coffee shops, we can help form them.
Each dot is a coffee shop, and the shaded spots around the dot represent the areas nearest each shop. It’s an interesting, more granular contrast to coffee chain geography and provides a better sense of a city’s layout.
See also the same idea applied to Cambridge. I imagine there are more cities to come, as the data is gleaned from the Google Places and Google Distance Matrix APIs.