[NOTE: With Google Earth 4 you just find the “3D Buildings” layer in the Layers pane on the lower left. Also, updated to add Japan with 3D buildings.]
Another feature not found by some beginning users of Google Earth is the 3D buildings layer. You turn on the “Buildings” option and, for 38 of the largest cities in the US, and many cities in Japan, Google has created 3D models of the many buildings in that city. Try Chicago, Illinois for example. Make sure, after you turn it on, that you use the “Tilt” feature as I described in an earlier entry.
Some enterprising guys posted their own smaller town in 3D at the GE Community BBS with a very nice model of their company’s (@ Last Software) building in Boulder, Colorado. Here is their post, and you can open their version 
of Boulder, Colorado in 3D. This is just a precursor of potential ways of advertising your business using the Google Earth.
[NOTE: if you aren’t seeing mountains, make sure the “Terrain” layer is turned on.]
Sightseeing
Google Earth Community Layer
[EDIT 2008: Google removed the ability to open the GEC layer folder so all the placemarks appear under the same layer. The placemarks are still useful, but it makes it harder to view the information in a categorized fashion and reduce the clutter. Hopefully they will return to a more organized sub-layer format.]
[EDIT January 31, 2006: changed the story to reflect the current name of this layer: Google Earth Community Layer, and to reflect some of the improvements to the clutter problem.]
Layers are the links to Google Earth’s databases of place marks including dining locations, roads, railroad tracks, etc. Right now, many of the layers of data are pretty much confined to the US (although many countries have the Roads layer and Airports layer). Over time they will add other countries to the different layer types.
Some beginning users are slow to notice the Google Earth Community (GEC) layers. These layers simply a database of placemarks which were posted by people in the forums with a link back to the post if you open the placemark. As people discover things, they post a placemark about it at the Google Earth Community. Then a month or so later, Google processes these placemarks and adds them to the GEC layers.
Earth’s Night and Day
Trying to add further realism to the conditions of the Earth, I like to see where the night and day side of the Earth is at the moment. Someone recently posted a new attempt at showing the Earth’s night and day conditions, and it updates automatically every 10 minutes.
I prefer to just leave this in My Places and turn it on when I want to see where the sun is setting or rising at the moment. Turn it off to continue browsing without this extra image interfering with your view.
Lost Ladder on Google’s Roof
I was browsing the new high resolution data for Google’s headquarters in California and noticed someone left a ladder on their roof! I thought this was pretty amusing so I posted a placemark in the GE Community forums. Check out the ladder for yourself. 🙂
It turns out I was one of several who posted about the ladder in the forums. Some people added amusing thoughts like: “How do you find a lost ladder at Google? Do a search in Google Earth!” or “Evidence of a Google Crime Scene”. Add your own picture title in the comments here for more fun.
World Wide Panorama
In a post last month Thomas Rauscher announced his places file which allows you to view the locations and access the neat panorama photos from around the world courtesy of The World Wide Panorama.
Most of the panoramas use the Quicktime VR plugin, so you have to have Quicktime with the VR viewer installed from Apple. I like the way Thomas has added photos of the panorama in each placemark and links to the panorama photos themselves. The links take you to the World Wide Panorama web page for the specific panorama.