With the new release of Google Earth (4.2) , it might be worth taking a quick look at how we might use it in teaching and learning. George Siemens argues that this is the sort of inspirational resource that educators and educational institutions should be focussing our resources on developing, rather than focusing on Learning Management Systems.
The easy place to start is looking at what people are already doing with Google Earth, whether in formal education or not.
Brian Romans started a Where on (Google)Earth? Quiz on his blog. This developed into a community effort. People try to work out where the screenshots taken in Google Earth are from. For example here is an example of a question and an answer.
Bowdoin College in Brunswick, Maine, USA is an example of an institution who have created a KMZ file which if you open will turn the campus in Google Earth into quite a complete campus map with 3D buildings, photos and annotations. You can learn about creating 3D buildings on the Google Sketchup site if that is of interest to you. Also you can add photos at panoramio.com; see the post on my experiences if you want to know more.
While there might be no reason for creating a campus map from a teaching and learning point of view, you might want to create annotations or use existing resources to bring an issue that you are covering in an academic programme to life. Google Earth Outreach has helped non-profit organisations work on this, for example those raising awareness of deforestation in the Amazon.
For more ideas, have a look at Google Earth Community discussion boards specifically the Educators discussion board.
Frank Taylors 'Google Earth Blog' is a great place to go to keep track of developments and uses for the software in the future. Subscribe to it's RSS Feed with your feed reader. If you don't have one and want to start subscribing to blogs, it is worth getting a Bloglines account.
More technical information can be found at Stefan Geens' Blog 'Ogle Earth' and at 'Google Earth Hacks'.