In July I began a test through Google Reader by means of which I made podcast feeds you could subscribe to and that would bring in assorted podcasts that can not be had in the regular fashion. Just now I have found an on-line service that does exactly that and more. Not only can you stick any file from a podcast in a feed of your own, you can insert audio files that are not syndicated. As long as you know the URL to the audio files, you can make the feed. For yourself and for others.
This is Huffduffer. Needless to say, I have started using it and found it to be extremely easy to use - especially with a plug-in in my browser that allows to right-click a URL and choose to insert the file into a feed.
I have chosen a number of lecture series that are on-line, but not syndicated and have turned them to feeds. J. Drabinski's lecture series about Husserl (feed) and about Heidegger (feed) - found through Baxter Wood. The Open Yale course about the Hebrew Bible by Christina Hayes that was not syndicated, when all the other Yale courses were. I devised a feed that contains all but the 15th lecture - for some reason Huffduffer cannot deal with that one. And lastly I made a feed for the Marathan Interview with Herman Bianchi (Dutch).
I will use Huffduffer to arrange special feeds for readers (come, come with the requests). You can do it yourself as well and I will be happy to publish and review when relevant.