EarthObserver App released on iTunes (it’s free for a limited time)

An iPhone and iPad App put together by Columbia University. From the iTunes Description:

Explore your planet as never before with the mobility of EarthObserver. Use your fingertips to travel through terrestrial landscapes and across the ocean floor. Visit frozen icecaps, study geological maps, scout mountains to climb and trips on coastal waters and exploit a rich atlas of other earth and environmental imagery.