Astronomy tool for night sky viewing.

I would like to see an open source plug in to google map viewer to
allow a view of the night sky at a location and date/time. This would
be a great teaching tool. It would presumably work by finding your
location. post the date/time start - stop and show the stars and
general constellations/planets/moon for that time. Allow the viewer to
choose the viewing direction and azimuth. Is there anything in the
works?