The ‘TripIt’ tool has taken off in the past year as a tool to publish and share one’s calendar which does starts to set the foundation for ‘where we are available’ collaboration (‘Where We Are Available’, ‘Make Office Better’). It does require a manual process of checking out the TripIt alerts of connections to see if they are relevant or intersecting with your own plans. The ideal solution will be an alert that hits you when a connection and you are going to be within X miles of each other for a period of at least Y hours.