Lilia Efimova collected links to papers presented at the AAAI 2006 Symposium on Computational Approaches to Analyzing Weblogs.
Speaking of the AAAI Weblog Symposium, some organizers from that meeting and the WWW '06 Weblog Ecosystem Symposium have banded together to launch a new standalone weblog conference: the International Conference on Weblogs and Social Media (site down as of this writing). The conference will first meet in March '07, with a submission deadline of November '06, if I remember correctly.