AutoCADder

AutoCAD is able to export KML/KMZ models to Google Earth already for some time (since version 2007 and its GE Extension). The recently released new version of the Google Earth Extension for AutoCAD 2008 adds very interesting functions to the previous plain PublishKML command.

One of the new functions allows to work with the "4th dimension" - you can add timespan attributes to your published models and then use the time-slider in Google Earth to animate the building process, the existing/new changes, etc.

Another new function is IMPORTGEMESH. This command imports a 3D model from Google Earth window to a 3D mesh in AutoCAD. The model has even attached materials (the raster images - aerials) so you can simply render it.

This is a very nice add-on for AutoCAD - a must for any civil engineer.

Further reading:
http://autodesk.blogs.com/between_the_lines/2007/05/publish_to_goog.html (announcement)
http://labs.autodesk.com/utilities/google_earth_extension_beta/ (download)
http://www.cadforum.cz/cadforum_en/qaID.asp?tip=5593 (step by step)
http://earth.google.com (Google Earth)