CS Professor Jon Kleinberg was a keynote speaker at the ACM Conference on Hypertext and Hypermedia (Hypertext 2008) in Pittsburgh. He spoke on "Link Structures, Information Flow, and Social Processes".
http://www.sigweb.org/ht08/keynote.html
Jon was also an invited plenary speaker at the 2008 annual meeting of the Society for Industrial and Applied Mathematics (SIAM) in San Diego. His talk was entitled, "The Geography of Social and Information Networks".