Actually, WalkScore just seems more geared to comparing smaller towns and less dense cities, and doesn't work as well in comparing different neighborhoods within a city. I noticed my own walk score at the apartment my lover and I are moving to is pretty high, but partially it's because the "nearest grocery" is a bodega and the "nearest library" is a medical library at a hospital.
Update: Another oddity, they also seem to have not ranked this whole section in the middle here:
The missing chunk includes Prospect Park, lower Crown Heights, Prospect Lefferts Gardens, and Flatbush. (Upper Crown Heights has been divided between Bedford-Stuyvesant and Fort Greene, into which Prospect Heights and Clinton Hill have both been subsumed.)
