This started me thinking about the power of field trips and what it really means to have a student that has never left the town they live in. Then I thought of all the powerul tools we have to give students "virtual" field trips. Google Earth is a great venue to make this happen. With the ability to turn on different layers you can take the basic sattelite images and explore anywhere you want to go, includign the ocean. Turn on 3D building layer and see the skyline of major cities, or of historic sites like the Alamo.
Here is a quick tutorial on how to use layers in Google Earth.