A user of an instant messaging system may store names of other users of the instant messaging system on a participant list (which may be referred to as a “buddy list”), and the names may be categorized into one or more groups. Similarly, a user of a mobile device, such as a mobile telephone, may...http://www.google.com.au/patents/US7124370?utm_source=gb-gplus-sharePatent US7124370 - Presence and geographic location notification based on a delegation model
