"Shanghai Noon" is a Jackie Chan flick set in the Old West. If that inventive screwball setup isn't enough by itself to get you itching to see the movie, please feel free to read on.

The sanguine sovereign of the kung-fu caper comedy, Chan stars as a subservient Chinese imperial guard who is part of a rescue party dispatched to America in pursuit of a kidnapped princess (Lucy Liu from "Ally McBeal"), who is being ransomed by a traitorous expatriate and his cowboy cohorts in Carson City, circa 1881.

After he's separated from his high-born countrymen during a railroad robbery Chan resolves to rescue the princess himself and reluctantly buddies up with the ever-glib, handsomely broken-nosed Owen Wilson ("Bottle Rocket," "The Minus Man," "The Haunting"), one of the incompetent outlaws who stuck up the train.

While the ingenuously charming Chan is having a blast injecting his Buster Keaton-inspired martial arts shtick into a cowboys-and-Indians motif (train-top-fu, pine branch-fu, Sioux-fu, Saloon-fight-fu), Wilson starts stealing scenes himself with his trademarked, peculiarly casual, unruffled smirks of mirth.

The ideal ironic cowboy, his whole performance is like Indiana Jones in that moment from "Raiders of the Lost Ark" when the crowd parts, the Egyptian swordsman threateningly spins his huge blade, then an exhausted Indy rolls his eyes and just shoots the guy. Wilson has that sense of farcical horseplay ingrained in his personality, and it makes for great odd-couple chemistry with Chan as they accidentally become wanted men when their individual nemeses (the kidnappers and a crooked local sheriff) gang up on them.

An endless array of hilarious Western high jinks are supplied by writers Alfred Gough and Miles Millar (they wrote "Lethal Weapon 4"), but rookie director Tom Dey wisely lets these two journeyman comics have their improvisational way with the script. The result is a movie that never stops being capriciously entertaining even during lulls in the action.

"Shanghai Noon" could have done with more of Chan's endlessly inventive fight scenes, and it feels much longer than its 105 minutes. But the only place the movie really falls down is in its criminal neglect of its potentially great female characters.

Perfectly cast as the kidnapped princess, the beautiful, saucy Lucy Liu is wasted when it comes to the action. You know that girl could kick some serious ass, but Dey confines her to damsel-in-distress mode. She gets off exactly three karate kicks in the course of the film. What a bummer.

Then there's the Indian girl Chan accidentally marries after getting fractured on a peace pipe with some friendly natives. Every time he and Wilson get themselves in a fix, she shows up to rescue them with some sharp shooting, then disappears completely -- frequently without as much as a word of dialogue -- until they're in trouble again.

"Shanghai Noon" has the same capricious, winking take on Westerns as the 1994 film version of "Maverick." But at least in that picture Jodie Foster got a piece of the action, playing flirtatious, self-sufficient foil to Mel Gibson's glib hero. The girls in this movie might as well be props.