KML is the most common data format for displaying geographic information, with over half a billion KML files on the web. However, much of the world's geographic information is also in other file types, particularly shapefiles, and image data. Fortunately, there's an open source utility library that helps developers work with all sort of Geographic file types, the Geospatial Data Abstraction Library. We've taken just two of the utilities in GDAL, and wrote articles about them.
Converting GIS Vector Data to KML: This tutorial walks you through the basics of converting GIS vector data to KML using the OGR open source library.
Creating super-overlays with gdal2tiles: This tutorial walks you through the basics of creating a super-overlay, a set of ground overlays that use region-based NetworkLinks, using the open source gdal2tiles utility. [...]
Read more: http://googlegeodevelopers.blogspot.com/2009/09/displaying-worlds-information-new.html