In our latest release (2.88) of the API, we’ve added “click” events to GPolyline and GPolygon, much to the enthusiasm of developers in the forum.
I knew it was just a matter of time since their internal apps have been supporting clickable GPolylines and GPolygons for some time now. Read the whole post for some fascinating information on how click detection works.
What this boils down to (for me anyway) is that you can display information generated with Google’s MyMaps interface on your own site with the same fidelity as the original via KML and GGeoXml. Up until now you could load KML from MyMaps via GGeoXml but the GPolylines and GPololygons only displayed and were not clickable. This removes a huge roadblock and should allow for even more interesting mapping applications.