Somewhat related, I just discovered PyEphem, and have been using it to pin down a time and location from the stars that appear in XKCD #1190<p><a href="http://forums.xkcd.com/viewtopic.php?f=7&t=101043&p=3395021#p3394991" rel="nofollow">http://forums.xkcd.com/viewtopic.php?f=7&t=101043&p=3395021#...</a><p><a href="http://rhodesmill.org/pyephem/" rel="nofollow">http://rhodesmill.org/pyephem/</a>