NewsGrowler is a simple command-line Perl script that watches an RSS feed and sends Growl messages when there are updates. This was written to address a specific need, but I decided to do it generically in order to make it usable outside of that one situation.
Please jump in and help out if you have any ideas of where this project can go from here. Post on the discussion board. Comment here. Fork the project and send pull requests. Or email me.