With the advent of social networking sites  such as myspace and facebook, the social sciences are suddenly awash in data.  Analysis of this data is the subject of much recent research.  See:


The following seminar webpage has a good description of the field:
http://www.dagstuhl.de/en/program/calendar/semhp/?semid=30825

This presentation at FOCS 06 by Jon Kleinberg is an excellent starting point.

There are many other papers on this subject.  Check out Jon Kleinberg's webpage or ask Amin for more info.