I came across the creating Interoperable Data. This topic has some interesting areas that allows for content to be transmitted across the internet.
The first post I came across was this one by David Raynes where he commented on the idea of “More like this from others”. After reading a bit more about it I came across this post by Six Apart which toyed and commented more on the idea.
Ben Hammersley has built a plug-in which uses Trackback and RSS well.
http://www.benhammersley.com/archives/003371.html