Podcasts are also something I am already familiar with. Colleagues have shared podcasts about subjects we are interested in with me. I have found websites for kids to use while researching that contain podcasts. For example, when the 8th grade was doing their career unit, I found podcasts about various careers on one college's career center's page. Last week, I found a collection of podcasts containing the stories of Holocaust survivors. I like finding resources using this technology because I think the kids become more engaged when they are listening to stories than when they merely read them.
I had never used a podcast directory before this. It is a good tool, but I don't think I could turn kids loose to use one. There is too much trashy stuff listed in the directories. It would be too easy for students to wander off into places you didn't want them to go if you had them use a directory to search for a podcast. I would have to find the podcast myself, then post that link in order to keep the lesson on track.
I like the idea of students creating their own podcasts. I would need to work on the tech part of doing this, but it is something I could develop in the future. I like the idea of linking the podcasts to your RSS feeder. What a good way to keep up with developments in fields you are interested in.