Alan, this series is great. Coincidentally I came across it courtesy of Greg McVerry (#) after having spent some time over the past few days discussing feed discovery with David Shanske who recently wrote a small WordPress plugin for helping to uncover RSS feeds for tags and categories. Today he wrote some broader thoughts about feed discovery you may appreciate. In addition to all of this, since you’re a coder, you might also appreciate some of the more advanced feed discovery code David has written into the Yarns Microsub Server for WordPress (code on Github). You may be able to build some of the discovery bits into some of your syndication hubs/planets in the future. Of course, like FeedWordPress and the relatively similar PressForward plugin, you might also be able to bend Yarns into an aggregator in similar ways.