Kids will dig the big-screen adaptation of Louis Sachar's best-selling, award-winning book about a group of delinquent boys who get caught up in an age-old curse as they shovel holes to ''build character'' in a desert camp. The well-orchestrated mix of realism (merciless authority figures castigate youngsters) and magical fable (an unsuspecting boy's familial legacy causes weird things to happen) brings to mind a certain other wildly popular kids' book. (Think wizards.) But this tale is more grounded, with a prematurely mature Shia LaBeouf (''The Battle of Shaker Heights'') sagely leading a spirited group of young actors. EXTRAS Buried treasure's more like it: Extensive interviews with actors and crew (including screenwriter Sachar), a gag reel, deleted scenes, and two commentaries leave no stone unturned.