I've always toyed with the idea of going to Burning Man but I'm turned off by how popular (read: the big, comfy trailers and the stratification of attendees) it has become. Is there a retreat that still is all about art / society-in-a-box?
I'm not a burner, but I've worked with several. There seems to be local community burner gatherings that are less well known unless you are part of the community and probably have the vibe are you seeking.
type "[your state] burn" into your favorite search engine, you'll find smaller events with a decent chunk of crossover with the people who are serious about Black Rock City.