Sir Roger Penrose gave two presentations at the Mathematical Sciences Research Institute in March. The videos of his presentations are now available. Check them out at:
http://www.msri.org/communications/vmath/VMathVideosSpecial/penrose/

Before the Big Bang and Twistor Theory, Old and New are accompanied with lecture notes that are also downloadable as pdf files.

ENJOY!

I just came across this podcast by Christopher Frederick, a graduate student in the mathematics department at Colorado State University. He talks about the math behind everyday topics. He has a interesting presentation and makes the topic appealing.

Check him out at: http://www.mathgrad.com/

He’s given 10 episodes since the beginning of 2006.