A mood state may be modeled using mood information for a content selection (e.g., a digitally-encoded song) and/or by using mood information determined by how a user is interacting with a media player. For example, a playlist engine on a host may determine that a particular song is associated with an...http://www.google.co.uk/patents/US20060170945?utm_source=gb-gplus-sharePatent US20060170945 - Mood-based organization and display of instant messenger buddy lists
