Interstellar Navigation by Dead Reckoning
Aside: so much for YouTube. Lousy job of encoding and it lost my soundtrack. So I rustled up some quick code and voila.
My favorite science fiction writer wrote a novel in 1967, give or take, called The Killing Machine in which the hero is attempting to locate a planet without precise coordinates, but has the assistance of a native of that planet who can remember the constellations of the night sky. The hero gets to what he believes is the correct "region" of space and asks her to look for a familiar constellation, because that will be direction to the star system in question.
This may seem far-fetched, but it's actually extremely practical (insofar as anything involving interstellar travel is practical).
I've never really looked into the technique in detail, but there's some discussion right now of a clue that the obsessive fans of Battlestar Galactica (the new series of course) who have noticed in the latest episode The Ties That Bind the constellation Orion showing up in several space shots. This would indicate that they must be getting close to Earth...
Now some folks have dismissed this, saying that it's bad science and they'd need to be incredibly close to Earth to recognize any constellations. These folks are just dead wrong. The two brightest stars in Orion are Betelgeuse and Rigel which are extremely bright and distant stars. The belt, similarly, is composed of distant stars. Orion would be easy to recognise from a considerable distance -- if you were looking straight towards Sol.
The video I've attached demonstrates all this using the wonderful free program Celestia. The upshot: Orion is easily recognizable from over one hundred light years out from Sol (assuming you're on the far side of Sol from Orion) and every other constellation is distorted beyond recognition.