[A note from several years ago, appropriate since we're headed to Firenze for a long weekend...]
RT @Slojuk @FrommersTravel World's Most Walkable Cities.
Florence is more than walkable. My father was able to (accidentally) drive straight through the Piazza della Repubblica -- to the (minimal) shock and (mostly) amusement of the locals. In my father's defense, I was the co-pilot, and neither of us knew how to escape the maze of one-way streets. The easiest thing to do was drive through the piazza to get to the Arno River.