Caped crusaders are big in movies, and they're also found in reality, as this documentary shows. Interviewees include several self-proclaimed real-life superheroes, like "Zimmer," a gay superhero from Brooklyn, N.Y.; "Mr. Xtreme" and "The Vigilante Spider," who sometimes team up in San Diego; and "Master Legend," who lives in Orlando, Fla., and has an otherwise typical life with his girlfriend. Some take themselves seriously, others don't. But all want to help humanity in their own way.