I just got my EVO and downloaded Sky Map. I was blown away that I could point my phone into the sky and have the stars show up like as if it was a window to the stars. Does anyone know exactly how this works? I know GPS only gives a point on the surface of the earth. Gyros can tell if the phone is turned and what not. I was thinking before I started that app that I'd have to calibrate it to a particular star before use like some of the telescope stabilizers. How does it know exactly where to point right out of the box?