From W3C Wiki
Suppose I'm travelling to Boston and San Francisco in the next couple months. I'd like my machine to let me know I have a FriendOfaFriend who also lives there or plans to be there.
So let's all put our travel schedules in the SemanticWeb so that we can find path crossings. See TravelTools.
earlier work: SWWS: An RDF Calendar Trial, DanConnolly et. al., Aug 2001.
Biglumber - key signing coordination XML 2004 event