Galaxies, Stars and Planets
I saw a post on Make today of a collection of high-resolution (2750x2300) image scans of the 30 color plates from Alexander Jamieson's 1822 (almost 200 years old!) star atlas. Courtesy of the United States Naval Observatory Library. I'm sure many can think of lots of ways to use this beautiful antique art.
Anyway, while perusing antique star charts it reminded me that I had come across a really cool little application recently that I haven't heard much about. Celestia, written by Chris Laurel, is like Google Earth for space. Even if you are not an astronomer, this little graphics application offers the opportunity to see the galaxy in a totally different way.
Update: Removed or updated dead links.