I have looked at the Podcasts and I was impressed with how much material is out there--this is true for all the other applications we have been experiementing with in 23 things.
For some podcasts I discovered that I would have to download some software in order to get the podcast but I went to Podcast.net and successfully signed up for a classical radio station. It appears to have frequent postings.
As for the question "What did I find useful here?---It was another experience in the great wealth of material that is out there on the internet. We are experiencing the different senses on the internet--You Tube was visual and Podcast is auditory. You Tube of course has the advantage that it can be auditory as well. Podcast Feeds on your blogline is a good way to keep abreast of those auditory things that interest you.