Aggregating RSS

I really like Jesse Ezell’s.net Weblog Archives (even though he didn’t spell my name right at first! 😄 Here’s my feature request: Filtering. I already subscribe to many of the currently archived feeds. I’d love to be able to filter those out of the RSS feed. Since RSS retrieval is a simple GET, the list of filtered feeds would need to be stored on the server side. Or you POST up the list of filtered feeds and get back the filtered aggregate RSS. Aggregating and archiving RSS seems to be hot right now, so a standard mechanism for filtering would be appreciated. My vote: lets expose a web service to retrieve aggregate RSS information.