Yeah, as to what Jamie said, I think Sal is just looking for that one perfect "roadin life to just pop up so he can take it in finally be content. I think he hopes that by travelling across the whole country and trying to "dig" everything, he can cover the most area and have the highest chance of his path to heaven appearing (since he obviously doesn't want to actually work to make his own path).
Anyway, I think that this section really establishes itself as a much more optimistic section than the last one and a refreshing change. Sal and Dean actually enjoy California for once and meet all of those crazy musicians. Also, they make plans to go to Italy, which would be pretty interesting to see, although I highly doubt it will ever happen. Most importantly though, Dean and Sal establish this really deep friendship, deeper than just Sal's attachment to Dean's insanity before; this makes this chapter one of the most meaningful so far. It seems that Sal now finally appreciates Dean as a human, and sees his sad side of being abandoned by his family and now needing friends to fill that gap. I thought that whole scene with the fight in the cafe was really poignant, and establishes the two characters as really complex figures.
We also see a lot of humorous elements in these chapters. I also thought that the whole scene with Dean driving the wrong way with the tourist family was hysterical. I actually thought that the scene where he's getting yelled at by all of the girls was also kind of funny, since Galatea is criticizing him for leaving Camille all alone with the baby (even though she kicked him out) and at the same time warning him that Camille will kill him if he tries to come back. It's just like, what do you want him to do? And through it all, Dean's just sitting there, with his goofy smile and goofy thumb stuck up (symbolizing his life of hitchiking). Ok I'm done.