http://www.youtube.com/watch?v=qbdVs6cx6oY
Per a request made here - we have added the final portion (Part 3) of the Dr. Robert Cathcart lecture up on our youtube channel - Rationale for High Doses of Ascorbate.
I don't think seeing this part of the lecture requires a playlist, but I will find out.
p.s. We are currently updating the Foundation's video page(s) to embed these videos.