This looks like a cool set of RSS services. I wonder what Mr. Winer thinks. I will play with these a bit and tell you what I think.
xFruits Teaches Your Feeds New Tricks
xFruits is a suite of RSS services that teaches your feeds all kinds of new tricks. For example, you can use xFruits to create a PDF from your feed, roll up several feeds into one, add a mobile feed or even post to RSS via email. It also rolls all xFruits users into a community.