"Creating your own filters: You have several options to create filters of your own on any site. Here are a few:
Take a look at previously mentioned FeedRinse, which filters out posts for your individual subscriptions by keyword, tag, author, and even profanity.
Another option, if you're a Chrome and Google Reader user, is the Google Reader Filter by Feed/Folder userscript. This adds a filtering box above your feeds to weed out words for an individual subscription or an entire folder.
Probably the most robust RSS feed hacking tool is much-discussed Yahoo Pipes, which combines many feeds into one sortable, filterable, and translatable feed (see how to use it here)."
Via Howard Rheingold, Dennis T OConnor