A pair of slacker hunter-gatherers (Jack Black and Michael Cera) are banished from their village and set off on a journey through ancient times in this tepid comedy. The Harold Ramis film (go figure) is amusing at times and elicits a few laughs, but the screenplay is in dire need of rewriting, because what we get here plays like a run-through of a first draft. The stoner crowd may appreciate the silliness after a few tokes. Oliver Platt, David Cross and Hank Azaria costar. 100 minutes. DVD INFO: Includes a commentary track, deleted scenes, extended and alternate scenes, line-o-rama, a gag reel, featurette and, on the unrated version, an alternate ending.