The sex product market has always been geared toward heavy-breathing guys. MyPleasure.com is different in that it targets women. It offers vibrators and other sex toys in a congenial setting, more like that of Williams-Sonoma than some of the raunchier sites for men. At the forefront of this effort is Melissa Levy, director of new business for the San Francisco-based firm, who reaches her audience through a variety of channels, including the Web, e-mail and a new catalog. Levy, who holds an MBA and is a veteran of the dot-com revolution, comes from a