Rodeo Drive went Downtown recently when Salvatore Ferragamo had an opening party for artist Johnny Swet. For the night, the boutique was converted into a guerrilla art gallery, with canvas wrapped over clothing racks serving as displays for Swet's art. Rodeo Drive types mingled with young actors and models, with the occasional drag queen thrown in for necessary street credibility. The event, a fund-raiser for Design Industries Foundation For Aids (DIFFA), was worlds away from the staid events and high teas of neighboring boutiques. "Lets just say this is one of the most interesting mixes of people this street has seen in a long time," said managing director Gary Nelson.