As I noted in the listing of Wi-Fi directories, Wi-Fi-Freespot Directory, www.wififreespot.com, focuses on free hotspots. This is a good starting place if you are looking for no-cost Wi-Fi public access. It is also worth noting that some of the big telecom providers give free Wi-Fi access to users who subscribe to some of their other services. For example, Verizon provides free Wi-Fi hotspots in many downtown New York locations to their DSL subscribers.
Most of the free hotspots fall into one of three categories:
Provided by a business in the hope of drawing traffic
Provided by a library as a public service (see the following discussion)
Provided by a local community (see the following discussion)
It's really worth browsing Wi-Fi-Freespot to see what local businesses you can find that provide free Wi-Fi. You'll probably be absolutely amazed at how many there are. (I know, I know, my community, Berkeley, California is not typical of anything, but there are literally hundreds here.)
Many public libraries provide Wi-Fi access that is free to the public (or at least to members of the community who have registered for a library card). The Wireless Librarian has a great directory of Wi-Fi availability in libraries:
Wireless Communities, www.personaltelco.net/index.cgi/WirelessCommunities, provides information about community-maintained Wi-Fi hotspots all over the world. This is worth checking out. You'll be surprised at how many community-based providers of free Wi-Fi networks there are, and the passion and commitment of the people and communities that provide this public service.
Here are a few sample wireless communities:
Bay Area Wireless Users Group (BAWUG) is one of the pioneering free Wi-Fi organizations. In addition to BAWUG's other activities, they maintain a number of free hotspots centered around the Presidio in San Francisco. www.bawug.org
Almost every university and college in the United States offers free Wi-Fi access to its students. This access is not, in most cases, available to the general public. However, if you are attending college, or plan to start next year, it is very likely that your alma mater will provide convenient Wi-Fi access for you. You should check with your school to learn the details of the Wi-Fi access provided, and to see if there are any special Wi-Fi equipment requirements.
Detroit Wireless Project (DWP) helps maintain a number of free hotspots in downtown Detroit. www.dwp.org
Personal Telco Project (PTP) has over a hundred hotspots in Portland, Oregon, and has contributed to Portland's being named the "hottest" city or city with the most hotspots in the United States for several years running. www.personaltelco.net/static/index.html
Seattle Wireless, in addition to supported hotspots around the Seattle area, has pioneered an alternative public backbone for wireless networking. www.seattlewireless.net