The sequence "A Human's Guide to Words" is now available as a professionally read podcast.
We have started working on the large "Reductionism" sequence which includes both the "Joy in the Merely Real" and the "Zombies" sub-sequences. They should be available in a couple of weeks.
I followed the link, but it isn't clear what my $5 pays for. A button says "Download", but when I click it, it tells me I need to buy a subscription. I don't want to do it if it means I have to go through iTunes, or click on a whole bunch of links to download individual MP3 files. I want to pay $5 and get a zip file of MP3s.
One of our customers uses a Firefox plugin called downThemAll which, given an podcast feed, will download all the MP3s for you. I suspect this will most closely resemble the outcome you're looking for.