I installed Google Earth on my iPod Touch the other day and have found it to be a great app. I went to my Gran's today who has no Internet connection (and there is no nearby WiFi connections either), I went into Google Earth and was told that as there was no connection, it would use the cache, I continued and then asked it to find my current location expecting it to say it couldn't as there was no Internet connection but instead it actually found my location and went straight to my Gran's house!!!!

Can anyone explain how it managed this? It's very clever!