Google has brilliant APIs for using their Maps, Google Earth plugin, Fusion Tables (online data tables), and other visualizations. What's so fun about your Fusion Tables is that you can view them in various formats such as the Table, different Charts, and also on the Map visualization, showing point locations or polygon geometries of areas. To help you out, they give you various tools for formatting your points and geometries and various interfaces for exporting your KML (keyhole markup language, xml file for managing all manner of geographic features and overlays - basically what Google Earth uses. here's an example, generated by my Fusion Table data) so you can embed Maps and Earths on your own pages with your Fusion Table data, or view it in Google Earth application..
The problem is, they don't currently export your style information in the KML files, so your Maps and Earth objects, unless you format them yourself programatically, use unappealing default styles - the geometries you export are opaque white, so overlapping geometries will be indistinguishable and forget about seeing what's on the ground beneath them.
There's an open enhancement ticket for this feature, so if you have a Google account (gmail, etc) please go to http://code.google.com/p/
fusion-tables/issues/detail? id=36 and "star" the item, letting developers know that this feature is highly desired in the near future.
In the near future I'll take you on a little tour of Fusion Tables and how to use it for Maps and Earth applications.