Not sure how closely you are following Internet Explorer 8 development, but they do have one cool new feature called Web Slices.  This will let you subscribe to only a section of a web page, and easily delete them when they are no longer needed.  You can now use this Internet Explorer 8 feature of the future now in Firefox.
WebChunks is a Firefox 3’s implementation of Microsoft Web Slices.  It allows you to “follow” an area of a web [...]