I've been working in similar directions as this - in an attempt to resolve the questions, "Can you have good discussion across the blogosphere?", "What is the nature of that discussion?" and "How does it differ from message-board conversation?". And I think the answer lies - yet again - in going back to the beginning and looking at the way the web in general (and weblogs in particular) operate like an academic citation network.
Building a bridge to Bacon can be done on the web, where there are specially designed databases with half a million actors. Most actors can reach Bacon within 3 links, and are said to have a Bacon number of 3. In fact, the average Bacon number is 2.920. But many major stars have lower Bacon numbers. For example, Keith Chegwin has a Bacon number of 2, because Cheggers was in "House!" with Miriam Margolyes, who was in "Balto" with Kevin Bacon.
Paul Erdos was a prolific mathematician who wrote academic papers with a total of 502 co-authors, more than twice as many co-authors as any other mathematician. So if you wrote a paper with Erdos, then you have an Erdos number of 1, and if you wrote a paper with someone who wrote a paper with Erdos then you have an Erdos number of 2, and so on. There are 337,000 mathematicians who can be linked to Erdos in this way.
the physicist Brian Greene had a clear lead with an Erdos-Bacon score of 5. He appeared in "Frequency" with John Di Benedetto, who was in ""Sleepers" with Kevin Bacon. And he wrote a paper with Shing-Tung Yau, who wrote a paper with Ronald Graham, who wrote a paper with Erdos. This gives a combined number of 2 + 3 = 5.
There were rumours that Erdos appeared in ���, which would have given him an Erdos-Bacon number of 3, blowing away all competition. However, official sources can find no evidence for a movie credit for Erdos. Brian Greene�s only serious rival appeared this year, when Dave Bayer, mathematical consultant to "A Beautiful Mind", was given a minor role in the film and equalled the record.