Tonight’s The Nationals, Yeasayer and Plants and Animals show at Central Park’s SummerStage is sold out. But wait! You can still get tickets if you sign on to Facebook! Gothamist reports that New York comic Mike Birbiglia (who has a Web site, MySpace, Flickr and Twitter blog) is promising to give two tickets to the Facebooker who can write the nicest thing on his "wall." No heckling allowed!