this website might be of interest:
Visual Who is a tool for visualizing an electronic community. Using data
such as mailing list subscriptions, it creates a spring based model of the
patterns of affiliation within the community. By varying the groups chosen
as anchor points, the user can interactively explore the underlying social
and organizational structure. The resulting image of the community can be
used as the basis for visualizing other data, such as the patterns of
activity found in the record of login and idle times.
The goal of Visual Who is to make the social patterns of an electronic
community visible. This paper discusses Visual Who within the context both
of social interface design and of data visualization."