minimap Firefox Extension adds GeoRSS to your sidebar
minimap is a Firefox extension that adds a very feature rich geo-sidebar to your Firefox browser (also available as a Flock plugin).

The extension offers incredible integration with online mapping and search services. When you first open the extension, you see a Google Map to which you can add locations or just explore. You can also drag and drop addresses, plain text or Microformats - minimap also offers Operator support - which show up on your map as saved locations. At any of these locations you can get directions, view in other mapping services, find books or services at the location, or general local search Google, Platial, Tagzania, and hopefully more soon via OpenSearch-geo.
The newest release, 0.1.4.7, adds GeoRSS and KML support. You can drag and drop (or use the menus to add) any GeoRSS or KML link and the markers will show up in the sidebar map.
So now you can view your feeds from services like Mapufacture or your Yahoo Pipes mashups within your browser and mix it with content you’re viewing on a site.