John Tropea has an amazing ability to keep in his head (and subsequently on his posts) a big map of all the related tools and applications that are remotely related to any given topic.

As a result of his encyclopedic knowledge of all things RSS/Attention/Recommendation, he has written a lengthy post about various applications of APML in every day web 2.0 tools.

He has a fantastic view of an APML enabled world that puts the user at the center of their Attention driven experience.

Read it here.