Stellarium is cool.
But this would be cool, too, tell me if it exists yet or not:
software that not only shows you what the sky on your own planet looks like, but allows you to display what the sky would look like from other locations in the solar system. So, for instance, what does the sky look like from the sun? From Mars? What does the big dipper look like from Mars? Polaris is the polar star here on Earth, but what is the polar star up on Mars? How recognizable are the constellations from other planets? Or do we lose all perspective on them? At what point do we lose that after you depart the Earth?
All of these questions seem like they should be entirely within the realm of accumulated data, so some sort of software ought to be able to help us out. Really it ought to just be a plugin feature of any astronomy program. Hurry up and make that, internet!