A friend did this last year (during a long stint of unemployment). Mostly couch surfing and bumming rides from friends.
She seemed to have a blast. I want to say she "visited" 17 different cities. Visit being defined as some stays only lasting 4 hours, others a few days. She used it to visit a few places she had not been to yet, and also to interview for some jobs across the nation, to attend a national trade convention for her profession (and interview while there) and also to meet with grad school friends that are now spread out all over the country. For the price of two domestic plane tix, it was a really good deal for her.
Retired in 2013 at age 33. Keeping busy reading, blogging, relaxing, gaming, and enjoying the outdoors with my wife and 3 kids (4, 10, and 11).