I've had some number of posts over the past couple months related to network theory and complexity, and each day it seems as if there are more applications and questions that revolve around these topics. Here are some good sites if you are interestedin learning more about such topics.
Northwestern University IGERT Program on Complex Systems
Notre Dame's Center for Complex Network Research (Albert-Laszlo Barabasi's group)
Santa Fe Institute (dedicated to complexity science)
One can find all sorts of papers and outlines of the research programs...good stuff!