Lectures on String and M theories http://online.itp.ucsb.edu/online/dual/banks2/ The above also contains sound files by Tom Banks explaining what is going on. If anyone is interested in this fascinating area of modern physics, it's worth reading/listening. Another one I just remembered was a lecture by Witten, a leader in this field. It can be viewed here, http://online.itp.ucsb.edu/online/plecture/witten/
