Gabriel Stempinski is an evangelist of the new sharing economy, author, documentary producer, and San Francisco city ambassador for CouchSurfing. We spoke about how new, sharing-themed tech startups are reshaping the economic and social landscape. Environmental and population issues are at the heart of our conversation and community makes more than a cameo appearance. Gabriel responds directly to Andrew Keen's critique of social media, but there are also some indirect connections to Jan Lundberg's sense of an energy crisis and Alexander Rose's discussion of long-term thought.