An instant messaging application intelligently infers a user's unavailability from one or more indicia which include the user's electronic calendar. Preferably, the instant messaging application may report not only that a user is unavailable, but also give a reason for inferring unavailability, in order...http://www.google.com.au/patents/US7337210?utm_source=gb-gplus-sharePatent US7337210 - Method and apparatus for determining availability of a user of an instant messaging application
