I have finally updated the list of US cities and counties that have large scale Wi-Fi networks: citywide WiFi for public access and government/municipal applications, and Wi-Fi hotzones. A word of caution: the list may not be as accurate as I’d like it to be. I’m hoping people will post comments to correct the entries. There are 110 municipalities with citywide WiFi that is open to the public for Internet access. In addition, there are 56 cities that have citywide or near citywide coverage but they use it only for government applications, mostly public safety. Finally there are 84 cities that have large outdoor Wi-Fi hotzones, mostly in downtown areas and parks.
You can download the list of US cities and counties with large WiFi networks from Scribd (PDF format).