In the middle of Rome's trendiest neighborhood, surrounded by sushi restaurants and nightclubs with names like Rodeo Steakhouse and Love Story, sits the ancient world's biggest garbage dump--a 150-foot-tall mountain of discarded Roman amphorae, the shipping drums of the ancient world. It takes about 20 minutes to walk around Monte Testaccio, from the Latin testa and Italian cocci, both meaning "potsherd." But despite its size--almost a mile in circumference--it's easy to walk by and not really notice unless you are headed for some excellent pizza at Velavevodetto, a restaurant literally stuck into the mountain's side. Most local residents don't know...