On a July afternoon I watch a man named Paul rap in the park. His song, "I Am a Fossil Fuel," is amplified by a sound system hooked up to his bicycle. Nate "The Juice Peddler" hands out smoothies, guacamole, and hummus made with a pedal-powered blender built onto his bicycle.
In the quiet of early morning, the unmusical clanging of glass bottles can be heard a block away. Tex moves slowly along San Francisco’s 25th Street, his heavy-duty Costco shopping cart loaded as efficiently as a mule packed by a master guide.
