Nearly everything had to go. A few months after losing her administrative job in the summer of 2008, 23-year-old Brianna Karp got rid of her furniture, a beloved piano, and most of her books so she could move back in with her parents. When that didn't work out, she moved into an old trailer a relative had left her, settling into an informal homeless community in a Wal-Mart parking lot in Brea, Calif. By the summer of 2009, she was living without electricity, regular showers, home-cooked food, and most basic conveniences.