Pitting kids against grown-ups has always been a reliable source of comedy; and Big Fat Liar indulges the "smart kid vs. dumb adult" fantasy with infectious enthusiasm. In this case it's Frankie Muniz from TV's Malcolm in the Middle; playing a Michigan eighth-grader whose penchant for lying results in parental scorn when he claims that a Hollywood movie mogul (ace character actor Paul Giamatti) has stolen the kid's hastily written English essay and turned it into his upcoming summer blockbuster. The kid only wants to prove his honesty and recruits his girlfriend (spunky TV star Amanda Bynes) to beat the honcho on his Hollywood turf. Elaborate practical jokes and slapstick gags turn this kid stuff (scripted and produced by two former child stars) into an enjoyable send-up of Hollywood absurdity. When combined with Giamatti's mastery of slow-burning megalomania; the show-biz in-jokes and Home Alone-style anarchy make this a harmless diversion for the young and young-at-heart. --Jeff Shannon