AideRSS provides 2 tools for enhancing Google Reader in Firefox, through PostRank post score, which you can use to filter and track the performance of any RSS feed.
-Identify best content with PostRank in GoogleReader:
-Adjust and filter any RSS feed - reclaim your time:
-Find the needle in the haystack and boost your productivity:
-Visually group stories by source and Thematic PostRank:
This Google Reader enhancement can be installed in 2 ways: through a Greasemonkey script or a Firefox add-on.