I have been spending a great deal of time working on a KML rendering
application called GraphEarth. The application is designed to create
3D thematic graphs such as Prism, chloropleth and bar (Extruded
shape). Furthermore, one can embed 2D Charts via a simple GUI and the
Google Charts API. The first beta release can be found at
http://www.graphearth.com. We have tried to do as much bug testing as
possible and are indeed aware of a few. Any feedback would be very
much appreciated. I am working hard to bring in some new map types as
quickly as possible. The application has a simple shreadsheet
interface and supports importing of CSV files from excel or any other
spreadsheet application.