Is a porn star with a heart of gold as much of a Hollywood concoction as a hooker with a heart of gold? It's tempting to call the two equally bogus, except that the starlets of the skin world -- a few of them, at any rate -- really do come off as slumming middle-class ''nice'' girls. Thanks largely to the market force of their websites, what they radiate, as much as sex, is control over themselves as commodities. In ''The Girl Next Door'', Matthew (Emile Hirsch), a diligent overachiever about to go off to college, meets the sweet, blond, rockin'-bodied Danielle (Elisha Cuthbert), who moves into his neighborhood to house-sit for her aunt. The picture is a virtual remake of ''Risky Business,'' only with little of the style or mood of the earlier film. Hirsch, an appealing actor with thick eyebrows that suggest a furtive inner life, hasn't been given the chance to match Tom Cruise's smashing dual projection of joy and shame. For half an hour or so, I hated the pandering flatness of what I was seeing, like the obligatory Peeping Tom scene, in which Matthew, staring out his window to the strains of percolating synth-pop, watches Danielle undress, and we're prodded to think there's something deeply soulful about his fixation on her tawny curves.
Yet ''The Girl Next Door'' won me over -- sort of. ''Risky Business'' had a great opening act and then descended into contrivances. This genial cardboard knockoff is contrived from the start but gets better as it goes along. Matthew has to rescue Danielle from a sleazy producer played by Timothy Olyphant, who walks an amusing line between goofy and threatening as he flashes a grin of stupendous creepiness. Elisha Cuthbert, from ''24,'' is a standard laddie-mag fantasy babe (I could hardly remember, scene to scene, what she actually looked like), but that makes her right for the role of a girl who wandered into porn and wants out of it, since no guy desires her for her real self. Hirsch and his geek friends, of course, have to take on the dirty-video world by entering it. These days, that's not such a leap.