Take Only Pictures, Leave Only Footprints

Traveling around the U.S., you can make free use of computers, including e-mail facilities, by simply visiting the computer centers in the libraries of most state universities.  These large facilities are rarely barred to the public at large, and their computers are also free to use - cheaper than cyber cafés!

Another source would be most public libraries - free, although some suggest a small contribution which is still far less than a commercial venture publicizing this capability. 

Some campgrounds are beginning to install hookups, generally in a lounge area or other facility where you bring your own laptop computer in and set it up.