I have been meaning to post about this, and John’s note below finally nudged me into action. If you haven’t already downloaded and played with Google Earth, you should. It’s a great, free program for learning all about our world. On top of that (and it’s a big “that” to top), the newest release added two cool things. The lesser of the two cool things is a built-in flight simulator, so you can literally fly through the 3-D Google Earth world. The second, way-cool thing, is Google Sky.
Imagine Google Earth, where they took satellite images of every square meter of the planet and created a 3-D browsable world, turned inside out. Instead of looking down on our planet, you can look upwards at our universe. They took a huge array space imagery, incluing Hubble (I believe), and mapped it to a 3-D surface users can literally skim across, and zoom in and out through. Add to that data layers with constellations and other cool astronomical information, and you get an amazing tool for learning about our universe. Pick it up! Link.