Uncovering Connections on Twitter Could Become Big Business

http://www.readwriteweb.com/archives/influencers_on_twitter.php

Still one of the most useful tools in this group, if still largely a proof of concept, is Pete Warden's Mailana. Give Mailana a Twitter username and it will tell you who the top 20 people that user has had reciprocal public conversations with on Twitter - who they are engaging with the most.

Interesting way to look at relationships.  Also interesting to think an entire industry can spin up so quickly around a single space.