Buster Keaton, the "Great Stone Face"
He was a vaudeville performer from the age of four, a silent-film star in his 20s, and the writer and director of some of the greatest comedy films ever made. Yet Buster Keaton never quite achieved the fame of Charlie Chaplin, and, at the peak of his success as an independent filmmaker, he signed a studio deal that he would call "the worst mistake of my life." Correspondent David Pogue talks with biographer Dana Stevens, and with comic actor Bill Irwin, about Keaton's artistic ingenuity, stunts, and innovations that inspire filmmakers to this day.