Let's credit innovation, however minuscule: It takes a wee bit of originality to make a teen flick in which the hero spends the entire time trying not to get laid. In 40 Days and 40 Nights, Matt (Josh Hartnett), a sweet-tempered San Francisco Web designer, gets dumped by his girlfriend and proceeds to console himself through a series of hot one-night stands with gorgeous, insatiable women. (Is this supposed to be the sad part of the story?) Matt, it seems, bags babes as easily as most men his age inhale. But as he lies next to them in bed, he doesn't see paradise; he sees the ceiling cracking open. (It's the abyss in his soul.) By the time he's reduced to faking an orgasm, Matt, an earnest if not exactly devout Catholic, decides to use the occasion of Lent to abstain from all sexual activity, including the solo variety, for 40 days and 40 nights. I'm not necessarily buying this any more than you are, but the movie is just undumb enough to tease us into wondering if this puritan program might actually do him some good.
Directed by Michael Lehmann, ''40 Days and 40 Nights'' is being marketed as a true-blue romantic comedy, but it's nothing more than American Pie with milder fruit filling. It's not half as witty as the famous ''Seinfeld'' episode, ''The Contest,'' that clearly helped inspire it. Matt, at first, embraces his celibacy like a born-again girl virgin of the Britney generation. He feels clean and in control, though I'm compelled to ask: When the movie celebrates his spirit to the tune of INXS' ''New Sensation,'' only to give us a montage of Matt tossing away porn tapes and Gear magazines, did anyone realize that the man singing the song, Michael Hutchence, is rumored to have died of autoerotic asphyxiation?
''40 Days and 40 Nights'' is all but designed to be an oglefest in spite of itself. As news of Matt's vow spreads on the Internet grapevine, the punchy geeks at his dotcom company organize the inevitable betting pool. His other coworkers are cutie-pie chicklets who dress like porn stars (these are Internet drones?), and when one tries to seduce him by flashing her thigh tattoo, the film veers off into standard teen-dog farce. There are Viagra jokes, boner jokes, and ersatz-Farrelly Dad-talks-about-sex jokes, none of them very funny.
But ''40 Days and 40 Nights'' gets better as it goes along, mostly because Josh Hartnett, with his hurtin' James Dean stare, does something unexpectedly charming. He convinces us that Matt truly wants to stay orgasm-free, even as he's reduced to a quivering jellypile of hormones, all so he can get back in touch with himself (so to speak). I wish that Shannyn Sossamon, as the girl he meets at a Laundromat, didn't have the cool, scrawny petulance of a self-satisfied model. But when she and Hartnett lie in bed, caressing each other with nothing but a white orchid, it's rather sweet. The hornier Matt grows, seeing bare breasts everywhere, the more his desire to sever sex from the masculine imperative -- the itchy demon of conquest -- seems a true crusade. ''40 Days and 40 Nights'' is just a kinder, gentler teensploitation comedy, but Hartnett's Matt, at least, invites the audience to graduate to something better.