For me, podcasts have replaced talk radio. I was an ardent talk radio listener and I still love it, but podcasts make the experience better. The champion of podcast, for me, is Dr. David van Nuys of Shrinkrapradio. Also the Skeptics' guide to the Universe and The Word Nerds have this great talk radio dynamic, but Dr. Dave is the best. Dr. Dave is also very innovative and he has begun to experiment in podcast with yet another feature of talk radio transported to podcast: phone in. On Sundays, beginning December 9th, at 10 AM Pacific time (check with your time zone) through Skype, phone and the web, listeners can participate in the recording of the podcast, talking and through the chat screen.
Co-host on these occasions will be Jerry Trumbule, friend and colleague of Dr. Dave and the person who allegedly pushed Dave into podcasting and thus fathered, in a way, Shrinkrapradio. I may participate myself, though the timing is a bit problematic for my time zone - exactly the time I have to put my kids to bed.
On December 2nd, there was a test run that can be heard. No listeners called in and only two hooked up to the chat (I was one of them). But that was on a short notice. I had just finished listening to the latest Shrinkrap when Dave announced the test run and I realized it was happening that very moment. I could participate for a minute but then had to turn my attention to my children again.