Faris plays Shelley Darlington, a Playboy bunny who lives at the mansion with Hugh Hefner and all the other bunnies. ("Girls Next Door" stars Kendra, Bridget, and Holly cameo as themselves, as does Hef.) On the occasion of her 27th birthday, Shelley is asked to move out, a victim of being "too old." Her male confidant, Hef's bartender, tells her that 27 "is like 57 in bunny years."

Dejected and with nowhere to go, Shelley ends up on the front step of a college sorority house; it reminds her of a miniature version of the mansion. She talks her way into a job as the "house mother" for the Zeta sorority. The members are all a bunch of dowdy self-decribed "losers" who can't find boyfriends. They are played by, among others, Superbad's Emma Stone, Demi Moore's look-alike daughter Rumer Willis, and former "American Idol" runner-up Katherine McPhee. You can no doubt see that The House Bunny follows the age-old movie formula of hiring beautiful young women to play "homely" girls. (Hey, they wear glasses and have their hair in ponytails! What man-repelling freaks!) This is no doubt because one of Shelley's chief duties is to glam the girls up so that they can attract new pledges and thereby avoid the imminent loss of their charter.

Right here is about where I expected the film to lose me. I figured that The House Bunny would be just another hollow story about how a group of girls learns a lesson about inner beauty by tapping into their outer bombshells. But guess what? The movie doesn't quite go like that. While Shelley teaches the girls about makeup, flirting, and the value of cleavage, she simultaneously ends up falling for Oliver (Colin Hanks), a nice guy who - get this - prefers a brainy chick to a vapid beauty. Just as she lifts their self-esteem through beauty and style tips, the Zeta girls lift hers by teaching her how to attract a man through intellect. By the end, the story is preaching a moral that's hard to argue with: young women are at their best when they feel good about themselves and are given the opportunity to demonstrate how capable and smart they really are.

But I don't want to make it seem like a message picture, because it isn't. It's an exuberantly silly comedy that just happens to have an admirable moral for the teen girls who are its primary audience. In today's cinematic world, were so many films aimed at the adolescent female audience send a message that women can only be defined by their ability to land a cute boyfriend, it's somewhat refreshing to see one that essentially says, "You can be awesome whether you have a man or not."

There are so many ways this material could have gone wrong, but mostly it doesn't, thanks in large part to Anna Faris. The actress often plays ditzy characters in her films, and that's true here. She really nails the kind of sublime airheadedness that has typified more than a few Playmates (*cough* Kendra Wilkinson *cough*). What's more, Faris always seems to find new ways of playing a ditz, so it never feels like she's repeating herself. Her character this time engages in a series of really loopy behaviors - saying people's names in an Exorcist voice, standing over steaming manholes so her skirt will billow up, etc. - yet Faris makes us empathize with her rather than ridicule her. She takes the trait of spaciness to a whole new level. Just look at the moment where Shelley bangs her head on a table and, in response, screams "great balls!" in front of a restaurant full of people. On paper, that line is pretty flat - juvenilia for its own sake. But Faris manages to infuse the line with such sincerity that it becomes one of the biggest laughs in the picture.

She's terrific, but for me, the real discovery of The House Bunny was Emma Stone. I had seen and liked her last year in Superbad and last week in The Rocker. Seeing her here, I was stuck by two things: One, how different she was in all three films; and two, how believable she was playing both sides of her character. Natalie is definitely on the geeky side. She yearns for coolness and grace, but they always seem to be just out of her grasp. Rather than going for stereotypes, Stone brings authenticity to the role, avoiding the pitfalls of being a pretty girl "ugly-ing it down" for a movie. Then, when Natalie and the others transform into swans, we feel her gaining confidence and recognizing the best qualities of herself. I think we have ourselves a young actress to watch here.

Not everything works. A subplot about the real reason Shelley was kicked out of the mansion is obvious way before the story ever gets there. It's also odd that the Zetas are repeatedly described as being unable to attract men, yet the Katherine McPhee character is pregnant. No explanation is ever given, nor is there any mention of who the father might be. A scene at the end, where Shelley gives an impassioned speech to the Greek counsel, is also a little too familiar.

Those things aside, there's enough here that works to allow for a recommendation. Screenwriters Karen McCullah Lutz and Kirsten Smith also penned Legally Blonde, and they once again weave together witty lines of dialogue, funny situations, and a suitable girl-power message. I laughed harder and more often than I expected to. And in the middle of it all are Anna Faris and Emma Stone, who take a potentially silly little picture and give it exactly the right kind of spunk.

( out of four)

The House Bunny is rated PG-13 for sex-related humor, partial nudity and brief strong language. The running time is 1 hour and 38 minutes.