research - Video lectures and presentations on quantitative finance

What are your favourite video lectures, presentations and talks available online?

A few rules:

• 
  

  Must be related to quantitative finance. No Economics 101 courses, please.

  
  



• 
  

  Try to avoid DIY lectures for wannabe Soros types (e.g. how to earn millions trading S&P 500 futures).

  
  


• Try to post specific links to freely available stuff.