ICTA is a (currently free) web-based system for automated text analysis and discovery of social networks from electronic communication such as emails, forums, blogs and chats.
Gruzd, Anatoliy A. (2009). ICTA - Internet Community Text Analyzer: Software for Automated Text and Social Network Analysis. Available at http://TextAnalytics.net
Carolyn Haythornthwaite posted this link to the AIR-L today.