How precise are height values determined with Google Earth? Is the precision for all areas, where 3D is available, the same or are there some differences?
Interesting comparision:
Stuttgart TV Tower (
http://skyscraperpage.com/cities/?buildingID=2661 ): 216.6 metres according entry, 216 metres according Google Earth
Nevertheless Google Earth has a problem with lattice towers like electricity pylons as such objects are not modelled properly and it does not work in rural areas as there are often no 3D-information available.