My mom shared a list of speeches with me on Facebook form a very prodigious program called TED. That stands for Technology, Entertainment and Design. Since this wiki deals with all three, I figured I'd repost; it's a great collection of really thought-provoking, challenging stuff.
http://mashable.com/2013/07/08/ted-talks-change-your-life/?utm_cid=mash-com-fb-main-link
You'll be glad you checked it out.