It seems like most of McKenna's stuff is turning up on Youtube these days as I just completed a marathon 62 item playlist set from one of his workshops recently. It's an awkward way to listen to a long long podcast but there are so many gems in there its worth the effort.
I intend to try and make clips of some of the shorter and more interesting soundbites that are more in the way of cultural observations as a 'gateway drug' to his longer sets like the one above which is touching, as I think it was organised by the Mathematician and friend Ralph Abraham at Berkeley where McKenna left his studies early in the late 60's and if I'm not mistaken Ralph still lectured. (Incidentally Ralph appears in the Spirit Molecule documentary too)
McKenna is unsurpassed when up against a home crowd of entheogen aficionados but here he wasn't always so sure of the crowd temperature and is thus slightly more cautious than usual though still connecting warmly with the mainly campus crowd. The full set is called Taxonomy of Illusion on Youtube.