As the HBO series Boardwalk Empire, which just wrapped its second season, gains popularity, it has made the 1920s the latest decade worth emulating. Come Dec. 31, Roaring Twenties parties will abound. "There is an enduring appeal to the images of the Twenties, added to by Boardwalk Empire, of this boozy, frolicking sexual awakening that has value right now," says Bryant Simon, a professor of history at Temple. "There is something about the formality, illicitness and exclusiveness that is popular," says Simon.