Here's an interview with Greenspan, one of the world's greatest practical economists. From Jon Stewart's The Daily Show. It's actually a really good bit about the basics of a monetary system. Stewart has a rep as a comedian, but shows here he's a more than competent general interviewer. Stewart doesn't pretend to be an expert, but he does get the expert to say some interesting things.
Most enlightening quote:
"... I’ve been in the forecasting business for 50 years. … I’m no better than I ever was, and nobody else is. Forecasting 50 years ago was as good or as bad as it is today. And the reason is that human nature hasn’t changed. We can’t improve ourselves.”
It's about 7:45 minutes.