SNARF: the Social Network and Relationship Finder (Microsoft Research)
Something cool to check out: SNARF.
SNARF was built around the notion that social network information that is already available to the computer system can be usefully reflected to the user: a message from a manager might be seen differently than a message from a stranger, for example. SNARF applies this idea to email triage: handling the flow of messages when time is short and mail is long.
The SNARF UI is designed to provide a quick overview of unread mail, organized by its importance. The UI shows a series of different panes with unread mail in them; each pane shows a list of authors of messages. Clicking on a name shows all messages involving that person.