When I was much younger, my dad used to show me things in the night sky. He isn't really an amateur astronomer - we didn't own a telescope, for instance, although we had some damned good binoculars - but he has a good idea of what's what up there, especially considering he makes his living looking mostly downwards. (A friend, the son of one of dad's co-workers, used to scandalize his father by saying "dad digs holes for a living" - they're soil scientists.) Dad also loves maps, which is good, again considering how he makes his living.
I have nowhere near as good an idea for what's what, either in the sky or on land maps, but I still appreciate things like Google Earth for the coolness they represent, and the night sky still holds some interest. Thus, OSXPlanet ranks right up there with Google Earth.