Demo and slides on social networks

Good item included in this morning's elearning post:
ReferralWeb
This is not a new site, but well worth a visit if you are exploring social networks. The PPT slides are especially useful in understanding the theory and the need for social network analysis. "The ReferralWeb system lets you search and explore social networks - the networks of friends, colleagues, and co-workers - that exist on the WWW. It lets you find trusted information from trusted experts, who are likely to help because they are friends of your friends!"
http://www.cs.washington.edu/homes/kautz/referralweb/