I haven't read that one, but it did make me remember one that my mom read and completely loved. I haven't read it myself, but she talked about it enough that I know it's about a woman who walked across the country... I think several times.
[ame="http://www.amazon.com/Peace-Pilgrim-Life-Work-Words/dp/0943734290"]Peace Pilgrim: Her Life and Work in Her Own Words: Peace Pilgrim: 9780943734293: Amazon.com: Books[/ame]
Mom read the hardcopy book, but it looks like they're now offering it for free download on the website.
http://www.peacepilgrim.com/FoPP/htm/book.htm
A family friend's son took a summer to walk the Appalachian trail, and it changed his life. He wound up walking it over and over again, found his now-fiancee at some point along the way.