There's plenty of camping sites, and places you can sneak off the road to camp without paying a fee. Some cities have hostels.
couchsurfing.com is a good spot for finding places where you can meet locals and stay at their place.
I'm in Sacramento, California and you can stay at my place. Only, no one goes through Sacramento because there's tons of good roads that go around it.
edited to add that at couchsurfing, I'm at:
CouchSurfing - Dave Smith
Last edited by Dave_Smith; 9 Nov 2007 at 01:00.