One of the interesting and recent applications of GML is to news feeds in Atom or RSS. This is an old idea – but one that has taken a major leap forward with the creation of a GML application schema for embedding geo-tags in RSS and ATOM feeds. While the formal schema has not been published this should be out pretty soon. To begin with it builds on simple GML geometries but has the scope for non-default coordinate reference systems and may be extended to use GML temporal constructs  in the future. Describing a hike or a sailboat race may never be the same.
For some examples and the GML Application Schema (soon to be posted) see http://georss.org/gml.html#examples .
Also look to this blog in the future as we will be looking at GeoRSS in the context of WFS and WRS, as well as offering some GeoRSS GML tips and guidelines.