Haven’t used Google news a great deal but I just realised that they collapse duplicate articles. At the end of an item there is a link called "related" which shows all other posts..I’m not sure how the system works out that 2 articles are alike.
Here is an example:
I’ve had a little experience on Newsgator but have found they sometimes have a link at the end of a post called "incoming links", I think this is collapsing duplicates as well. Maybe it’s exactly reflecting what the website, the feed is from, is doing. If the feeds website has a post that collapses duplicate links then when that post appears in Newsgator it does the same…I’m not sure on this one!
What about your personal RSS aggregator performing this same function as News Aggregators such as Google news. Now wouldn’t this be a great feature in Bloglines, I find so many posts are about the same thing within my account. I’d like one post, and all other posts about the same thing as a collapsable link at the end of the post.
But how would the system choose which post to show you amongst the others (maybe this could be done by previous reading behaviour, a la Chameleon, Findory)..choosing to show you the post that you read from the most.
The next question is that blog posts unlike news stories are unique in their own way, wandering in different directions, including off topic information…some are indepth reviews while others are re-published clips. In this respect not all posts are the same every time, even if the content covers mutual ground.
Regardless you could click on a link at the end of a post called "similar sub" that expands and shows you new links to other posts with similar content in your account (presumably the same content, similar is too broad in this respect). Now these are similar links to posts from feeds that you have subscribed to, in effect "your subscriptions".
I guess there could also be another link called "similar non-sub" which shows you the same/similar content to posts you aren’t subscribed to (a great discovery tool).
While you’re there the same could go for "past similar sub" and "past similar non-sub" showing you links in your cache that are similar in content to the new post…and so on.
You’d have to think of better label names for these links than I have quickly conjured up!