SAN FRANCISCO—After a few close friends personally escorted her around San Francisco's nicest parks, restaurants, and shopping centers, Virginia-native and first-time visitor Lori Timlin reported Sunday that she could envision herself living in the one of the nation's most expensive cities. "I can really see myself in one of those great big houses up on that hill, or maybe in an apartment overlooking the water," said the 28-year-old paralegal, whose friends had strategically steered her away from the city's aggressive homeless population and infuriating public transportation system. "How could you not want to live in a sparklingly clean city with such a perfect warm and sunny climate all year round?" During a four-hour layover at O'Hare Intern≠ational Airport on her trip back home, Timlin concluded she could never, ever live in Chicago.