B.Brown, I.McColl, M.Chalmers, A.Galani, C.Randell, and A.Steed (2003). Lessons from the lighthouse: Collaboration in a shared mixed reality system. In Proceedings of the CHI 2003 Conference on Human Factors in Computing Systems, pages 577–584, Fort Lauderdale, Florida. ACM Press: NY.

These findings have implications for non-museum settings, in particular how location awareness is a powerful resource for collaboration. (...) Shared awareness of location also allowed users to quickly move to their friends. Participants used this to quickly find what their friends were looking at and then move so as to look at the same thing. (...) Location awareness allowed participants to talk about and use each other’s context and navigation (...) Awareness of location also meant that users could better understand what their co-visitors were looking at; each could simply look at the map or 3D display, and see which exhibits the others were viewing. Location awareness might be similarly useful for other collaborative settings where current activity can be inferred from location

It's close to what I study in my research.