Place beans in a medium saucepan. Mash beans slightly with a potato masher. Stir in water and next 3 ingredients. Cover and bring to a boil over high heat; reduce heat, and simmer 8 minutes. Uncover, and cook 2 minutes or until soup is slightly thickened. Ladle soup evenly into each of 4 bowls; top evenly with Avocado-Lime Salsa, and, if desired, sour cream.
