Galaxy Quest

So thoroughly has ''Star Trek'' leeched on to the culture that the tatty, idealistic little sci-fi series that got axed after three seasons has now surpassed ''The Wizard of Oz'' as perhaps our prime multigenerational pop touchstone (all together now: Klingons and Romulans and Borgs -- oh my!).

But where last year's ''Trekkies'' proved that phaser-wielding fanboys could sustain a feature-length documentary, Galaxy Quest goes even further. It assumes that general audiences are so steeped in Starfleet arcana by now that they can both laugh at the geeks chasing the stars of a faux-''Trek'' series around the convention hall AND delight in the in-jokes that ping off the plot like so much space debris.

The movie holds this bifocal vision almost until the end -- when it turns squarely, unconvincingly sincere -- with Tim Allen, Sigourney Weaver, Tony Shalhoub, and Alan Rickman doing heroic double duty as out-of-work hams rising to the challenge of a genuine intergalactic mission; Enrico Colantoni (''Just Shoot Me'') scoring as a marble-mouthed alien; and a deeply funny Sam Rockwell as the crew member extra with an existential quandary over his status as ''lunch meat.'' Better and more meta than any real ''Star Trek'' movie, ''Galaxy Quest'' puts us all in touch with the Trekkie -- er, Trekk-ER -- within.