I just discovered the Mises Institutes iTunes University store
They have the entire set of Human Action by Mises on audio book for free.
All their stuff is free.
Its a virtual cornucopia of economic goodness.
You need iTunes installed for these links to work.
Human Action by Mises:
Thomas Woods, Robert Murphy, and Jeffery Tucker are a couple of my favorite speakers, so be sure to check out their work.
Particularly Murphy's lectures on Anarchism and the constitution.
The Evils of Intellectual Property:
Introduction to Anarchy:
JRR Tolkien as a Libertarian: