Frank at Google Earth Blogpoints out that the National Geographic Layer now contains plenty of placemarks over North America, not just Africa.
Remember that Google Earth 4.0 is _beta_. After some heavy use, my copy started to crash repeatedly as I zoomed over a specific region. Trashing the settings file didn’t help. Trashing the cache file did.
Notes on the political, social and scientific impact of networked digital maps and geospatial imagery, with a special focus on Google Earth.