That's a great tip, we3!
I saw all sorts of small rigs parked on the streets in west LA when I was there last year, ranging from $100k Zions to looks-like-it-might-not-run-at-all tumbledown C's. Offstreet might be more difficult, though.
You can't really boondock OUTSIDE of the SF bay area or LA, because those places are huge and you would have to drive for hours and hours just to get in or out of town. They do have RV parks, though. And LA has beach and mountain campgrounds, which are a pretty good deal.
3/4 timing in a DIY van conversion. Backroads, mountains, boondocking, sometimes big cities for a change of pace.