I can't leave it alone. The more I work with Google Earth 4 (GE4), the more I like it. What I've come to better appreciate is GE4's 3D buildings and terrain. In the shot that follows I'm looking at the Golden Gate bridge, with some of the higher terrain in the background (basically looking north towards Needles). The bridge itself is constructed from simple 3D elements, while the terrain seems to be molded, perhaps on a classic polygon surface. I don't know enough to say, but I'd sure be interested to find out.
This next shot shows the view down looking south-east at the intersection of Columbus and Kearny. The Sentinal building is directly in front, the Transamerica building is in the background to the left, and the 555 California Street Building is in the background on the far right. All three of these buildings were modeled, not just mapped blocks of grey.
Note the 'flat traffic' on Kearney to the right. It looks weird at first, but you get used to it rather quickly. I think it adds necessary detail without getting in the way. I don't think you should have to model the individual cars and general city furniture.
I ran GE4 under Gnome and Compiz this time just to see if that combination would have any adverse effects. It had absolutely none.
My only complaint so far with GE4 is in precise placement of a view with the mouse. I've noticed that attempting to get close to the ground or any large object causes the view to suddenly jump around. It takes some time, patience, and a light touch on the mouse to get close to where you want to be. But that's a minor complaint at best. No matter what, it's a great application.
And I've since discovered KML, so maybe I can add my own content. I took a look at Orlando, Florida, and it's absolutely flat. No 3D anywhere. I'm also looking for any official APIs in order to work programmatically with GE4.