Google Sky Map is a free Android application that helps users to learn about the sky using the handsets built-in GPS along with compass, date, and time functionality.
Google Sky Map help turns Android-powered mobile phones into a dynamic window of the night sky. When users point their Android powered handsets skywards map displaying the brightest stars, constellations and planets in that part of the sky appears on the screen.
Here’s a video demonstration of the Google Sky Map app.
Google Sky Map is available free from the Android Market.
http://www.google.com/sky/skymap.html