Some viral videos succeed because they are funny or shocking, but the best succeed because they expose viewers to a new idea that they want to share. In a trivial way, perhaps, that's what happened in a big way with Gangnam Style. Who knew you could dance like a horse? In a more serious—but still wildly entertaining—way, a new video sponsored by The American Heart Association's Go Red for Women program demonstrates a new idea about how to get active. "Follow Your Heart" (above) shows New York trainer Andia Winslow making her way from her apartment in Spanish Harlem to the subway station ... Read More