Gary Farber, the bestest blogger around who's shown up in my comments, links to a Locus
article in which Lucius Cook reviews Futurama in terms of treating science fiction literature as more than just material for pastiche. And he does so without even mentioning "The Sting," an episode which bears a striking resemblance to Philip K. Dick's A Maze Of Death. One does, however, get to read of Matt Groening implying that Heinlein possessed a sense of humor, not a suggestion one hears every day.