It is often easy to glaze over in most discussions of the semantic Web. Though I argue many places that it is a historical inevitablity that the federation of meaning (e.g., resolving semantic heterogeneities) that is the ultimate objective of the semantic Web is the next logical step to recent accomplishments in the resolving of physical and data syntax heterogeneities, such a statement hardly sounds or is compelling in itself.
That is why examples are so powerful.
TopQuadrant has posted a really cool mashup demo of the use of its TopBraid Composer semantic modeling toolset with Google Maps, all in the context of a standard geospatial OWL ontology. The demo also simply explains how all of the pieces work together and shows why OWL ontologies make sense in the first place. The demo also shows well the use of SPARQL, the RDF query language.
To see this video in action, choose the Geography and Mapping Support link from the http://www.topbraidcomposer.com/videos.html page.