Have you ever heard of this website... http://www.ted.com/
I've seen quite a few speeches on it over the years. It is basically a conference where some of the brightest minds come and share ideas. This years conferences are sold out already in Palm Spring, CA and Los Angeles, CA but there are still openings for the global conference in Scotland in July. I like to just watch them online.
Some of the speeches I really like are:
Sir Ken Robinson "Schools are killing Creativity" 2010
Sir Ken Robinson "Bring on the Revolution" 2009
Dean Kamen previews a new prosthetic arm 2007
Jamie Oliver's Teach Every Child About Food 2010
Hans Rosling "Global Population Growth" 2010
Hans Rosling "Best Stats" 2006
Hans Rosling "Let My DataSet Change your Mindset"
JK Rowling "Fringe Benefits of Failure" 2008
There are hundreds of varied topics and lot's of interesting ideas exchanged. When you get an extra 20 minutes in your day, type in a keyword you are interested in like education and see what speeches pop up and grab your attention. They are wonderful dinner party conversations and I always feel "smarter" after watching them.