This post is mainly a work-in-progress for me so I can get my thoughts together on GeoRSS.
http://www.georss.org is obviously the main source of info on GeoRSS … “GeoRSS is a simple proposal for RSS feeds to also be described by location or Geotagged”
There are two encoding systems being developed – GeoRSS GML and GeoRSS Simple. Each can encode a spatial reference as either a point, line, box or polygon and these references within XML or RDF are identified by a “georss:” namespace.
Why? Geotagging an RSS feed means you can present the feed on a map. This may sound gimmicky but imagine being able to see news, events, traffic problems etc. displayed on your favourite web mapping application? Google Maps seems particularly well-suited to this kind of integration.
See some examples
All of the above examples are cases where an RSS feed with geotagging is being taken and used together with the Google Maps API to produce a map of the feed items.
Other useful resouces