If you’ve got time and bandwidth to kill, you might want to check out TechTV. In the spirit of OpenCourseWare, MIT hosts videos of various guest lectures and conferences. For instance, Energy forecast for the rest of the century. Although I don’t personally agree with all of the professor’s interpretations—many conflict with the more pragmatic views portrayed in “Sustainable Energy,” which is incidentally available via OCW—it was an interesting presentation, and could probably serve as a good introduction for the uninitiated nevertheless. I also appreciated his putting the scope of human influence in perspective by comparing it with natural flows. It reminded me of prolific environmental author Vaclav Smil’s excellent Cycles of Life : Civilization and the Biosphere.