If you have astronomical imaging of the sky with celestial coordinates you do
not know or do not trust then is for you. Input an image and we'll give you
back astrometric calibration meta-data, plus lists of known objects falling
inside the field of view.Astrometry.net

We have built this astrometric calibration service to create correct,
standards-compliant astrometric meta-data for every useful astronomical image
ever taken, past and future, in any state of archival disarray. We hope this
will help organize, annotate and make searchable all the world's astronomical
information.

WWW: http://www.astrometry.net/