Sir Ken Robinson speaks eloquently about the importance of creativity in evolution and education. This Does Schools kill creativity? movie is a terrific 20-minute talk.
And TED.com is a terrific site, full of amazing talks in the form of movies and podcasts, about terrifically interesting subjects, by terrifically smart and coherent people. Each talk is delivered in front of an audience of luminaries (i.e. the speakers don’t have to dumb things down), and they have to stick to their 20-minute timeline, so they stay sharp.
In other words, whenever you have 20 minutes to kick back and would like your mind opened a little wider, check out this site. Nary a dud in there.