A new extension for Revit was just released today called Globe Link. Below are some details about it along with the link to the download page on the Autodesk Subscription site.
Globe Link for Revit 2009
Release Date: 2008-09-29
Globe Link for Revit 2009 platform products helps users streamline preliminary project planning processes by allowing them to present to clients conceptual designs in context with information about the project site.
With Globe Link, users can publish 3D building information models directly from Revit® Architecture 2009, Revit® Structure 2009, and Revit® MEP 2009 software into Google EarthTM mapping service. Users can also acquire site information from Google Earth mapping service and import it into Revit 2009 software applications for building and site layout purposes. Globe Link is optimized for Google Earth version 4 mapping service.
Globe Link is now compatible with the 32-bit and 64-bit versions of Revit Architecture 2009, Revit Structure 2009, and Revit MEP 2009 software.
Content is currently available in English only.
(you must be logged into the Autodesk Subscription site to access)