I have only recently jumped on the podcast bandwagon but I am really enjoying it. It makes my daily commutes on public transit significantly more interesting. One of the podcasts I found is Ologies hosted by Alie Ward and I absolutely love it. Alie talks with a different -ologist in each episode about a specific ology. While some of the episodes veer off into the less scientific (Gemology definitely went weird places), for the most part they are fascinating forays into different sciences with an appropriate amount of side notes and explanations from Alie when the expert gets a bit to technical.
And just to add a little social science to this post I looked up if there was any research regarding podcasts (not sure that pocastology is a thing yet but perhaps one day). Most of the research I found related to using podcasts to assist in language learning, particularly English language learning. This makes a lot of sense as listening and processing what is being said in an additional language can be a daunting task. I have tried learning French off and on and always find that I get frustrated because I never seem to be able to access French lessons that are relevant to what I want to learn (apparently not everyone wants to be able to say coniferous trees versus deciduous trees in French). With some applications of podcasts in language learning, students are able to choose ones that connect to their interests and proficiency levels. Yeh (2013) found that students found podcasts convenient for learning, that they enhanced their language proficiency, and world knowledge, and were generally satisfied with the experience. Not surprisingly though, the students were also frustrated at the fast speech rate in many podcasts.
Yeh, C. (2013). An investigation of a podcast learning project for extensive listening. Language Education in Asia, 4(2), 135-149. http://dx.doi.org/10.5746/LEiA/13/V4/I2/A04/Yeh