For the serious podcast listener, podcast lecture series can offer content for actual study. One such series is J. Drabinsky's teachings about Husserl. He calls this a podcast, but these (and other) lectures are actually not syndicated. With the help of Huffduffer, I have worked aroudn that and devised this feed: http://huffduffer.com/AnneisaMan/tags/husserl/rss.
Drabinsky's recordings allow you to listen in on his cycle on Husserl, which includes next to him teaching, the interaction with his students. These students are very knowledgeable and take Drabinsky with their questions to all direction, not only with Husserl, but also with other philosophers, whether Husserl's successor Heidegger, or the classical Aristotle and Plato. What arises is an thorough introduction into Husserl's thought and his philosophy called phenomenology, which, by Drabinsky, is characterized, more as a method, than a philosophy.
This method, is an tool to unify the sciences. And so, this course is also very much about science, knowledge and the acquisition of insight in the physical world. As complicated as that subject is, to begin with, the level of the course, both from the professor as well as the students, make it into a very taxing podcast. This is not for leisure listening - this is for serious study. And very worthwhile at that.
Dichter und Denker in Freiburg (review in English, podcast in German).