GDR Dycoec: French universitary think-tank group on complex systems.
Outreach initiatives
Collège de France: Online lectures on all aspects of science are freely available to everybody. In particular, the lecturers in physical sciences are extremely high profile scientists. Slides and multimedia files (audio/video) of the lectures are also available.
MIT OpenCourseWare:"Free lecture notes, exams, and videos from MIT. No registration required." MIT initiated few years ago this ambitious program of online lectures. A visionary and successful endeavor.
Scholarpedia: Wikipedia is undoubtedly one of the most important existing website. Scholarpedia obeys the same generic principles, except it is more dedicated to scholars. The encyclopedic articles are peer-reviewed, "dynamic, subject to an ongoing process of improvement moderated by their curators", so that they "are not frozen and outdated". And of course, they are free.