As I mentioned earlier much of my iPod listening involves podcasts dealing with critical thinking, skepticism and religion. In addition to a professional interest in ethics, creativity, and leadership, I have a layperson's interest in astronomy, evolutionary science, neurology, anthropology, history, politics. There are only so many hours in a lifetime so I look for ways to cram as much great content between my ears as possible. Enter the Applie iPod (the Touch in my case), iTunes, and iTunes U. There are a near endless supply of interesting lectures available on iTunes and iTunes U or at many host organizations' websites. There is no excuse for going without a cool content fix as often as you like.
The Kenan Institute for Ethics at Duke University has many podcasts dealing professional and business ethics, culture and human rights. Look for them at iTunes U.
Princeton University Podcasts features a wide variety of events and lectures in mp3 or mp4 formats. You can also score them at iTunes U.
Also sponsored by Princeton is the UChannel where you'll find lectures put on by many universities.
Royal Society for the encouragement of Arts, Manufactures, and Commerce (RSA) and The London School of Economics and Political Science (LSE) can be found on both iTunes U and iTunes or at their websites. I prefer the downloads from iTunes because I can listen to most of them at 2x speed. They have video podcasts too but I don't time enough for screens.
The Stanford Technology Ventures Program has seminars, lectures, and events related to leadership in the engineering and high-tech manufacturing sectors. You can access their podcasts at iTunes U or on their website; or you can stream their content directly to your PC.
ResearchChannel has a rich Health and Medicine Video section though much of the detail is above my head.
Ontario's public educational media organization produces a TVO Big Ideas podcast.
The Commonwealth Club of California is a well known staple to public radio listeners but those of you too busy to listen on the lunch hour can subscribe via iTunes or download from the site.
Gresham College has been offering free public lectures for 400 years, podcasts not quite so long...
NPR's On the Media is a weekly analysis of how the news is reported. Look for it at iTunes or stream or download the podcast from their site.
A person might be excused for mistaking a PopTech video podcast for an episode of TED as they address similar topics. Available as an audio podcast too.
TED brings together brightest lights from the fields of technology, entertainment, and design. TED has over 400 brief talks by some really brilliant people. You can sign up direct with them or via iTunes. Great stuff.
The thing I like best about all these resources is their generally optimistic tone. Perhaps the doers, the movers, and the shakers are too busy making things happen to worry about whether or not they can. There is a podcast for almost everyone. Find yours. Fill your brain.