Homelessness in Los Angeles has burst its traditional borders. These days, downtown's Skid Row is only the ugly epicenter of a staggering problem that radiates outward for more than one hundred miles. Homelessness has spread to gloomy underpasses and dark side streets, to parks, libraries, and subway platforms, so that there are now more than 50,000 people who lack a regular place to sleep in Los Angeles County. From Long Beach to Hollywood to Beverly...