It's enough to make Naomi Campbell hurl another phone. With Nicole Kidman in talks with Chanel -- and Jennifer Lopez and Christina Aguilera appearing in ads for Louis Vuitton and Versace, respectively -- celebrities are becoming the preferred faces for couture. ''People got a little tired of the supermodels,'' says Karen Lee, scouting director for NYC's Elite modeling agency. ''Actors appeal to a wider range of women, and the bottom line of the fashion business is to sell fabulous clothing.'' Since the typical supermodel is at least 5'9'' (sorry, Xtina) with classic 34-24-34 proportions (uh, sorry, J. Lo), how are designers coping? ''They have a fitting, then have everything recut and resewn -- they have to,'' says Neal Hamil, an executive VP at Ford Models Inc. Still, Gisele needn't weep into her fat-free latte just yet: ''It's easy to book a movie star, as long as you have money!'' says Hamil. ''But supermodels know how to make the clothes look good, turn their bodies the right way.... They understand clothes far more than an actress or entertainer ever will.''