AideRSS is a great service for helping you filter your feeds. It checks the number of comments (if possible), number of times it shows up on Google’s Blog search, how many people bookmarked it on Delicious and any diggs that story got on Digg to calculate the PostRank.
You can then setup each feed with one of these choices of filtering
- all posts
- good posts
- great posts
- best posts
- top 20
Once you save several feeds you can get a single feed made of the feeds you picked and what filtering you chose for each feed. You can even get a top stories based on all those feeds with whatever filtering you picked.
The data to calculate the PostRank is not send with the feed either, but I think their algorithm is good enough you won’t need it. One downside is that the category nodes are lost in the feeds. Which means you can’t filter these new feeds anymore with Yahoo Pipes based on the original categories, but they do send the PostRank in the feed. I suppose you could create the category filtered feed from Yahoo Pipes first, then grab that RSS feed and put it through AideRSS to filter it yet again. I really wish Google Reader offered some filtering options, and perhaps I wouldn’t have to use all these other sites.