Anyone who's even tangentially familiar with the Star Trek phenomenon can appreciate Galaxy Quest, a fast-paced romp combining sci-fi action with puckish observations on pop culture. It begins at a convention for fans of a TV cult favorite not unlike you-know-what. After answering the same old questions and signing a zillion autographs, the show's cast members -- played with tongue firmly in cheek by Tim Allen, Sigourney Weaver, Alan Rickman, and Tony Shalhoub -- are recruited by real aliens for their aid in fending off hostile invaders. Having intercepted rerun broadcasts, the aliens believe Allen and company to be authentic space soldiers. David Howard and Robert Gordon's script provokes laughs by plunging the actors into perilous situations from which they can extricate themselves only by responding as their series characters would. Affectionate spoofing of sci-fi traditions and a surfeit of in-jokes make Galaxy Quest a must-have for genre fans of the Star Trek generation.