Besides so-called "hotspots" (places like airport, where you often can get Wireless LAN) access, there are some projects, which try to provide a Wireless LAN for a whole city, region or country.
phpWirelessMap(http://phpwirelessmap.sourceforge.net/) is a set of PHP scripts created to generate dynamic maps for wireless communities web sites.
Wifimap(http://savannah.nongnu.org/projects/wifimap/) is an Web-based application that graphically documents the organisation and growth of a wireless network community. The map is composed of numerous square cells that are recombined to display the required area. Users can start with just a few cells to cover their area, and can access different areas of the network by scrolling through the cells.
phpKisMapper(http://www.no1atall.com/dev/phpkismapper/) is a PHP class which processes Kismet logfiles to create a map of wireless networks. Using the built-in XML parser and the GD library, the class reads GPS co-ordinates on wireless access points, downloads a map from the Web, and outputs the map with the recorded wireless APs.
From the Publisher:
"Building Wireless Community Networks
is about getting people online using wireless network technology. The 802.11b standard (also known as WiFi) makes it possible to network towns, schools, neighborhoods, small business, and almost any kind of organization. All that's required is a willingness to cooperate and share resources. The first edition of this book helped thousands of people engage in community networking activities. This revised and expanded edition adds coverage on new network monitoring tools and techniques, regulations affecting wireless deployment, and IP network administration, including DNS and IP Tunneling.