My favorite programming podcast is se-radio ( http://www.se-radio.net/ ) I especially like this one for getting a general overview of a variety of coding related categories and practices. Being self-taught, it's been been an invaluable source for broadening my basic understanding of the field. The guys that run the podcast definitely strike me as being more involved in the corporate space, but the topics are relevant to just about every topic in software construction, from episodes on embedded real-time systems, an interview on the internals of the gcc compiler, clojure, and tons of others.
I listen to This American Life frequently. The stories are always fascinating and well-produced.
Stuff You Should Know has always been one of my favorites. It's like spastically browsing the internet in audio form. You learn all kinds of super-interesting things, but never really learn much about any one subject. I'd suggest this for long car-trips when you're not trying to accomplish anything, heh. Love it, though.
howstuffworks.com has a lot of interesting ones outside of Stuff You Should Know, but I'd hit that one first.
those are my favorites, off the top of my head
History of Rome, Software Engineering Radio, This American Life, Stuff You Should Know
For other software-related podcasts, I recommend FLOSS Weekly (http://twit.tv/FLOSS). They cover interesting open source projects and interview their creators, as well as other influential people of the open source world.
He is very engaging and informed (he was / is an investigative journalist and a history buff, taking from multiple sources and citing biases or clashes with alternative sources.) http://www.dancarlin.com/disp.php/hharchive
He has a separate podcast "Common Sense" for politics.
Phil Windley (of Kynetx, local to UT) has diverse tech podcasts: http://www.windley.com/
Also, to feed my hunger for gadgetery, "The 404" and "Buzz out loud" from cNet.
And if you're into history Dan Carlin has two podcasts, "Common sense", about US politics, and "Hardcore History" on history. Good shows by a smart host.
Drive safely, and merry christmas!
Radiolab - unique stories (often science-based) and great production values
Know Tech is basically a geek conversation, but is biased towards Mac and video.
Independent Misinterpretations is the new podcast by James Robertson formerly of Cincom about Smalltalk and episodes about other dynamic languages.
A nice weekly round-up of current security issues. As well as some in-depth explanation of some aspect of security - like the inner workings of ssl certificates.
I also +1'd This American Life, and Radio Lab.
At some point I liked You Look Nice Today -- it is really funny, but intellectually vacuous.
Econtalk is quite good, but a bit dry.
Email is karan.bhangui@gmail.com
Decoder Ring Theatre at http://www.decoderringtheatre.com/ Bells in the batfry at http://thebatfry.com/.
Both are low frequency (DRT is twice a month, and batfry is when ever john bell feels like doing it), but I think they will remain my favourites.
Science, humor and World Robot Domination.