If you submit your astronomy photo to the Astrometry group on Flickr, a tool of the same name will look at the image, tell you the location of the field of view, and label all of the celestial objects contained within it. Here's an annotated photo of the Pleiades.
Your assignment: use the Astrometry and Exif data to stitch all these photos together into a huge Hockney-esque map of the sky. I am also wondering the extent to which you can fool Astrometry with, say, a painting of a portion of the sky. It would be neat if you could submit a drawing of a constellation and get the correct star IDs back. (via mouser)