GeoRSS :: Geographically Encoded Objects for RSS feeds
GeoRSS seeks to go beyond the x,y point location tag that currently exists in RSS 2 and leverage GML to support more complex geometry (lines and polygons). The overview sounds good with key ideas, such as linking related point entries into a line (their example was a kayak trip). They even seem to be attempting to implement a form of topology, but I may be reading too much into the document.
GeoRSS :: Geographically Encoded Objects for RSS feeds
Via SlashGISRS