Episode 4: Car Brain

Jeff and Tanya discuss the impressive turnout -- and possible pitfalls -- of London's 1,000-person die-in for cyclists' rights. We try to contain our envy (but not our amazement) at Paul Salopek's seven-year journey tracing the path of Homo sapiens from the Rift Valley to Tierra del Fuego. And we admit that yes, even passionate transit advocates know what it means to embarrassed about taking the bus.