I suspect that Google Sky’s main audience is going to be educators and amateur astronmers. For that matter, typing in 'Andromeda Galaxy' will accomplish the same thing. Type in M31 and you will be taken to the Andromeda Galaxy.

Google Sky also includes a search function. You can also zoom further out into the stars (to a certain point.) Google Sky uses the equatorial coordinate system (declination, right ascension) for location, rather than lat/long.

You’re looking at the dome of the stars, rather than a relatively flat map. Navigation takes a bit of getting used to. You can toggle constellations on or off, as well as information about the moon and the solar system. One can also add placemarks, polygons and overlays. These include Hubble telescope layers, and other points of interest for astronomy. As with Google Earth, there are layers that can be turned on and off. Google Sky uses actual astronomical photographs to create its image of the heavens, similar to the satellite imagery used in it’s terristrial counterpart.

The view below is what one would see if standing in my yard (assuming it weren’t mid-afternoon and that Haywood Mall’s lights didn’t obliterate the stars.) The time of day you click the button determines what you see overhead. I haven’t had a chance to explore this very much, but the view does appear to be time sensitive. A toggle button now appears on the toolbar that allows you to switch views.

You can basically toggle between views – looking downward, then looking upward from the exact same lat/long coordinates for a view of the night sky. Today Google released a new version of Google Earth, version 4.2, which includes a cool new feature called Google Sky.

Google sky view of my house