Check out this cool iPhone app, iPhone Earth, developed by Earthscape.
This cool iPhone app uses the phone’s accelerometers to allow for tilt and rotation when viewing the globe.
They weren’t downloading the imagery data over the net, it was all running local with just imagery for the San Francisco area. The application is under development using the Apple iPhone SDK.
Check out this video of it in action.
You can find out more information about the iPhone Earth app at the link below.