This was a pretty new "thang" for me as I hadn't previously accessed podcasts. I liked pocast.com quite a bit, and I think it could be my directory of choice for now. I was quite impressed with the range of topics covered, and I really liked its streamlined, simple interface. I listened to some BBC and NPR podcasts - very enjoyable!
There were extensive "book buzz" podcasts ranging from Nancy Pearl to one called Books on the Nightstand, which I loved. Try it out: http://books.podcast.com/show/83050/Books-on-the-Nightstand/
I'm not sure if I'll be podcasting myself in the near future, but I can definitely see adding podcast listening/viewing to my leisure activities. Thanks, 23 Things!