New York's historic South Street Seaport has recently become one of the city's trendiest destinations. On Friday night, just after sunset, about 300 people come here to dance in silence. From the outside it looks like a large-scale flash mob: crowds of people ...

New York's historic South Street Seaport has recently become one of the trendiest spots in the city. On Friday night, just after sunset, about 300 people come here to dance in silence. From the outside it looks like a large-scale flash mob: crowds of people in ...