Walkscore.com is a cool and fun resource widget which analyzes "walkability" ratings for the 40 largest cities in America. Today Walkscore.com announced that San Francisco is the most walkable city in America. I can attest to their rankings as I have lived in SF for 14 years, NYC for 1, Washington D.C., for 7, and LA for 5 fate-filled months.
The following is my original deansguide article on Walkscore (Aug 2007) my analysis of the good and not so good, and how to understand and utilize this cool tool:

In another of a plethora of fun widget sites, www.walkscore.com rates your home’s proximity to “walkable” landmarks, plotted on a map, within a neighborhood. The landmarks are then listed by name and address in the left sidebar for your convenience.
According to Walk Score: “ <!-- google_ad_section_start --> We help home buyers, renters, and real estate agents find houses and apartments in great neighborhoods. Walk Score shows you a map of what’s nearby and calculates a “Walk Score” for any property. Buying a house in a walkable neighborhood is good for your health and good for the environment.” For information on how Walk Score derives their “Walk Score follow this link: How It Works.
My SF Home
If you drill down on the “Walk Score” link provided above you will see that my former digs in San Francisco received a very high Walk Score of 91 out of a possible 100. This is a information rich tool and it does give any newbe to a neighborhood tons of ideas for exploration.
Issues or Curious Results?
On the other hand, the sensitivity to distance seems to be a real issue with Walk Score. Most of the bars and restaurants listed were within a few blocks (.25 of a mile) of my former address in the Lower Pacific Heights neighborhood of San Francisco. These bars and restaurants were mom and pop joints which I visited infrequently. Why? Fillmore Street was only 4 blocks away and crowded with some of the best restaurants, bars, and people watching in the city!
An example of the curious results: Walk Score’s listing of John Lee Hooker’s Blues Club “The Boom Boom Room” which is a long walk from my old condo. Why is this odd? They failed to list incredible world class restaurants that were half the distance yet reside on the same street (Fillmore Street) as the Boom Boom Room.
Transparency
In Walk Score’s favor is the fact that they provide a transparent page about why Walk Score doesn’t work called: “How It Doesn’t Work: Known Issues with Walk Score.”
I found this a saving grace and a very important reason to like Walk Score.
In the same vein as my questions about bar and restaurant choices within my San Francisco Walk Score, I was left to wonder why natural beauty was being left off the criteria list. I live on the water with full use of a boat dock, marina, and yacht club-I don’t own a boat. Yet Walk Score never took this into consideration when calculating my new suburban digs score. Even though all of these facilities are open to the public, within a stones throw of my doorstep, none of the water related facilities were mentioned in my scorecard.
New Digs Score: What about the Scenery?
Consequently my San Rafael score, a below average 31 out of 100, took an unfair beating in my opinion. But of course that is the fun of Walk Score-nobody will ever agree and it leaves tons of room for debate.
Idea
I would love to propose to the Walk Score folks the idea of a board game for adults. Make it a cross between “Charades” and “Mad Libs” with adults testing their neighborhood knowledge.
How To Get Walkscore Widget
To add your Walk Score widget to your blog or website go to www.walkscore.com and follow the simple instructions for your free widget.

Dean,
I was checking this out just today. What an awesome tool to link from your listing pages! I would definitely link a homes walkability. The only problem in my market is that those kind of homes are few and far between. Thats life here in the suburbs.