I love this program! Be forewarned that it is not super easy to use, but the combination of user interface and features simply cannot be beat. I tried many other programs, but Feeder is the only one that supports ALL fields for ALL feed types: podcasts (normal and iTunes podcasts), newsfeeds, etc.
Thanks to feeder our walki-talki.com rss/podcast need be rendered exactly once, and it runs EVERYWHERE.
Support from the developer has been excellent, and the value is superb if you consider that this is the only software you will need to generate all of your feeds.
And, there are so many creature comforts in this software: get mp3 data from the web, notify ping services, publish automatically to iTunes and ftp server, insert html tags (images and links), etc., etc. Great piece of software.