A nice 6-minute film from the American Museum of Natural History in which the viewer looks back, from a rocketship, as she moves from the surface of the planet through the universe. Various scientific landmarks and facts are displayed over the course of the trip (orbits of satellites, orbits of planets, extent of our radio communications). Good for kids and context. Make sure to max out the resolution – can go to 720.
And if that got you in the mood, try this: