In what is becoming a bona fide Letterman trend, Luke Wilson shared his favorite Tracy Morgan stories, complete with two short (but accurate) impressions of the comedian last night while on the show to promote Death at a Funeral, in which he stars as Morgan's best friend. It wasn't as intense as Tina Fey's much-talked-about Tracy impression on the show last week ("Jack Human!"), but Wilson paints a funny portrait of himself as the mild-mannered straight man to Tracy's outrageous persona ("I'ma pervert!") on set. After this, Letterman should institute a rule that everyone who appears on the show and has worked with Tracy Morgan has to tell a Tracy Morgan story — guaranteed good times.