Google Ancient Places is a Google-funded project to connect locations to their mentions in ancient literature, and then map them in Google Earth. Google tried a layer like this a few years back (see here) but it needed work. Perhaps this research grant will solve the semantic challenges.

The UK's Foreign & Commonwealth Office takes a stab at raising awareness of the impending effects of global climate change, using Google Earth. (Press release here)

Google Earth Enterprise shown being used as a unified aerial command-and-control visualization tool.