A couple great articles from O’Reilly on using social graphs to visualize data. Andrew Odewahn revisits and older project in Visualizing the Senate social graph, revisited – OReilly Radar. The basic notion is to go through senate voting sessions with each senator as a node. When there is a pattern of frequently having similar votes a node is drawn. He does this over an number of different periods giving insight into the political climate. Definetly watch the video.
Then he goes into how to improve upon the effort. The second post shows how to code this using Processing for a more interactive social graph analysis.