"Nobody believes a liar ... even when he is telling the truth!" That's the moral from the old Aesop's fable, and the foundation for Big Fat Liar, a modern-day retelling of "The Boy Who Cried Wolf."
Jason Shepard lies through his teeth from scene one, though not for attention -- it's just his way of surviving by using his God-given storytelling talent. And it works well up until his English teacher gets his number and demands his term paper pronto or it's off to that hell on earth, summer school. So he writes it. But through some wacky twists of fate, it ends up in the hands of a professional liar/Hollywood movie producer, Marty Wolf, who steals the goods for his own use. No one believes Jason's story, not even his father, so he and his girl-buddy Kaylee venture off to Universal Studios to prove Jason's truth.
In the land of child actors, Frankie Muniz and Amanda Bynes (Jason and Kaylee) are television superstars, possessing the personality and talent to headline their own shows: Muniz as that fretful and endearing Malcom from Fox's hyperrealistic family comedy "Malcom in the Middle," and Bynes as anything from a Mafioso princess to a television judge on Nickelodeon's "The Amanda Show."
The down side is the big bad Wolf, Paul Giamatti's first leading role, and quite possibly his last. Giamatti is a poor man's Chris Elliott, with the artificial air of a cartoon character trying to function in a multidimensional world, and he's half the film. The best bits are wrapped around the kids, not because they're cute and cuddly, but because they're just better actors with a greater sense of timing and execution, as well as the capacity to evoke sympathy for their characters.
It's too bad about Wolf's lackluster slapstick because Jason and Kaylee infiltrating Hollywood is a child's super fantasy filled with pink-feathered gorillas, free Coke and pinball, endless role-playing with the costumes at hand, and amusing, clever cameos with "The Six-Million Dollar Man" Lee Majors and Jaleel White (Urkel on "Family Matters") with a chicken.
The moral of this story is: Don't pair up two extraordinary, up-and-coming child actors with one low-caliber, two-bit adult goofball.