By Patrick Kevin Day and Whitney Friedlander Simon Pegg, left, and Nick Frost, third from left, are unabashed science-fiction geeks in real life and in their new comedy, "Paul." So it makes sense that their film, which they wrote the screenplay for, is filled to the alien gills with pop-culture and science-fiction references. Not a geek? Afraid you'll miss a reference? The following is a list of the major films every potential "Paul" viewer should have under his or her utility belt before setting foot in the theater. Of course, the movie works without knowing this stuff, but don't you want the satisfaction of nodding knowingly at your friends? Geeks love insider knowledge.