Each episode is only around 12 minutes, and over 60 episodes are now freely available via itunes or their own site.
I listened to the last half dozen yesterday. While the podcast focuses on the design world, the topics covered are astonishingly wire-ranging - from geodesci architectural design of the 1950s; to the 'Advance Teams' who stagemanage political rallies in the US election; to 'dazzle' camoflauge originally used by WWI naval commanders to confuse missile-firers; to the issues of the growing monopoloy of internet cable suppliers.
I was partcularly struck by the episode on Kowloon Walled City, which prior to its demolition in the 90s, was the most densely populated place on earth. Apparently, to reach the same population density, every single resident of Texas would have to have moved into Manhattan island to match the levels experienced in Kowloon.
Photographer Greg Girard has a great photoessay on the Daily Mail site (sorry, couldn't find it elsewhere...)