Podcasts of National Archives lectures

According to a snippet in Ancestors magazine (July 2006, p. 6) "you can now download podcasts of recent lectures given at The National Archives". More detailed instructions would be helpful. So far I can only find one example: a talk by Maxine Berg, Professor of History at the University of Warwick, about inventions in eighteenth-century Britain. The talk was originally presented at part of a TNA exhibition on Inventors and Inventions: Patents, Protest and Power in the Industrial Revolution 1750-1890.