BlogSieve – Creates New Feeds from Existing Feeds
http://www.blogsieve.com/

BlogSieve is a 100% free service that creates new feeds from existing feeds. With the constantly growing popularity of feeds (Atom, RDF and RSS) tools like BlogSieve gives you the opportunity to pre-process your news or syndicated website content. Since BlogSieve outputs the resulting processed feed in any format you choose it’s easy to use BlogSieve feeds with your existing newsreader application, web-based aggregator or even as content for you website. This has been added to my presentation resources page for Bots, Blogs and News Aggregators.