WalkScore is a site that rates towns and neighborhoods based on how easy it is to get around on foot - The way it works is essentially based on how close a place is to businesses. So in a way, the site is as much a measure of population density and zoning regulations as anything else.
When I think about the places I would want to live, it ultimately comes down to the single issue of how pedestrian-friendly the place is. Living in New York was great for this reason, and Lubbock, TX was terrible. As a kid, we lived across the street from a library, but the street was a 12-lane highway with no place to cross. We had to wait for my dad to come home with the car so that we could drive across the street.