What's Your "Walk Score?"

The good folks at Comment magazine, published by the Work Research Foundation, pointed me to Walkscore.com, a site that allows you to plot the "walkability" of your neighborhood, or to use as a tool when considering a move. Just type in your address, click, and see how your house rates. Our house scored a respectable 77. From first glance, it seems to me that the site should also factor walkability to public transit. But an interesting snapshot of one's built environment.