Windows/Mac/Linux (Firefox): AideRSS, an RSS feed popularity filter that Adam had a few bones to pick with, has released a free Firefox extension that integrates its popularity rankings into Google Reader. AideRSS says it uses the number of comments, Google backlinks, bookmarks on social sites like Digg, reddit, and del.icio.us, and more data to determine a PostRank, which it plugs next to each feed item and offers as a drop-down filter. While it’s obviously going to bias your reading against fresher posts that haven’t had time to make their mark, it might be helpful to anyone trying to cut down on RSS clutter. For their next version, let’s hope for an options dialogue to remove that PostRank number from every single post, as the filtering bar may be more useful to most users. AideRSS is a free download, works wherever Firefox does.