In this installment of Biblio Tech, we'll look at some sci-fi works that challenge classification but have become cult items. Each has become a perennial favorite with the sci-fi community, and several have become fixtures in the computer science community. Two of these works, Dark Star and Alien, are movies, while the other, The Hitchhikerýs Guide to the Galaxy, is part of an extended novel whose universe and characters have taken on lives of their own. All three play with interesting ideas.