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! ReferralWeb has been featured in The Wall Street Journal. Read more about the system in The Hidden Web, by Henry Kautz, Bart Selman, and Mehul Shah. The AI Magazine, vol. 18, no. 2, Summer 1997, pages 27 - 36, in Adobe Acrobat (pdf) format.
More details about ReferralWeb can be found in Mehul Shah's MIT MS thesis, ReferralWeb: A Resource Location System Guided by Personal Relations.
View a Powerpoint presentation about ReferralWeb including many screenshots
The ReferralWeb project was directed by Henry Kautz and Bart Selman. The system was first developed by Mehul Shah. The final implementation was created by Yooki Park.