I'm sure there must be software out there to do this. It's kind of a fun problem, but I really don't have time to tackle it.
Let's draw a social network graph of DC users.
Each node in the graph is an author, and links between authors are created when authors interact by posting in the same thread. The length of each link connecting two nodes is inversely proportional to the strength of their interaction, determined through the frequency of participation in the same threads. Each author
can be weighted by their authority, as determined by their propensity to spark discussions with many interactions.
What do you think? Make this general (i.e., for any forum) and you have a very cool plugin that people can stick to their forums