A couple of small tools :
RSS Backup : A script to save items from an RSS feed as distinct files on your local machine. Originally used to backup my answers on Quora it’s now generalized so you can save any RSS feed.
Planet Builder : I run a couple of copies of the old PlanetPlanet (a Python RSS aggregator) to create rivers of news about particularly interesting themes. These scripts make it easy for me to set-up new installations of PlanetPlanet.