No documentation. Appears to share an interface with HTML::GoogleMaps, but digging a bit reveals only the onload_render, center, add_polyline and load_kml methods are implemented. add_marker is, sadly, unimplemented.
Made me waste time because it declares a completely bogus dependency on the obsolete Geo::Google, but actually depends on Geo::Coder::Google.
Still, the only thing on CPAN among the dozen obsolete Google Maps modules which is a starting point at talking to the V3 API, and it is a 0.01 version, so in the spirit of "release early", two stars overall for now. Hopefully more features in future versions, or perhaps incorporation into HTML::GoogleMaps.