Sergio Sanchez stood behind Pope Francis at his Vatican inauguration ceremony, wide-eyed amid all the pomp, glitter and VIPs of a slice of history. That was Tuesday, but on Friday he was back at his job in Buenos Aires, hunting for anything useful in the city's garbage. Sanchez is a leader in one of Argentina's lowliest professions -- head of a 3,000-member garbage scavenger cooperative in the capital. But he was friends with Jorge Mario Bergoglio, archbishop of Buenos Aires, before Bergoglio became leader of the world's Catholics.