19. The one or more computer-readable storage media of claim 18 , wherein the set of indexed semantic user profiles is ranked at least in part based on social network data.
19. The one or more computer-readable storage media of claim 18 , wherein the set of indexed semantic user profiles is ranked at least in part based on social network data. 20. The one or more computer-readable storage media of claim 19 , wherein the social network data includes information on relationships between users, the information including at least one of: information on degrees of separation between users; or information regarding strength of relationships between users.