Stellarium Mobile is a fully-featured planetarium for your phone. It shows a realistic night sky map in 3D, just like what you see with the naked eye, binoculars or a telescope.
The sensor control will also enable you to identify what you see in the sky in just a few seconds, just by pointing the phone at it.
This award-winning astronomy application is available on Android, Symbian^3 and Maemo featuring:
The Quick Start Guide (pdf) [550Kb] describes how to get started with the application. It also provides an overview of the app if you want to learn more before trying it.
The OpenGL ES port- is already merged in the Stellarium source code trunk available on launchpad.