ADVANCE FOR THURSDAY, APRIL 11–Vivian, left, and Marian Brown, identical twins, shake a leg in their favorite city, San Francisco, on April 2, 1996 in front of the Transamerica building. The city has made Vivian and Marian its unofficial mascots, and they attend many public and private events. They also have made several commercials to augment their income.(AP Photo/Susan Ragan)