Burning Man

This about says it all.  I'm sure that a lot of BM is actually fun, cool, etc. 

But Chris is right in that there's a real oddness to it - a bunch of the "engaged" go into the desert, treat it like a parking lot, and make a ramshackle and temporary community of the largely similar (an actual demographic breakdown of attendees would be interesting). 

And as far as art being transformative goes, I'd rather simply talk to people where I live.  Perhaps ride my bike on roads that don't see many bicycles.