The people saying that Obi-Wan is one with the Force, the ultimate power in the Galaxy, pretty much have it spot on. Obi-Wan may not have become a god and destroyed Vader after death, but existing beyond the grave and being one with a powerful energy field is pretty damn impressive for Force-users. You have to remember that it was meant to be a rare trick.
Wasn't it something that required years of skill to achieve? Yoda mentioned it at the end of RotS about Qui-Gon "learning" and being able to teach Obi-Wan...
What I don't get is how Anakin became a force ghost when he had no apparent training - as he seemed too young - and then went straight into Sithhood...weird. Not sure if Sith teach about how to achieve force ghost status
I think he probably trained Luke when he was even sleeping. How else to show how Luke got to display such skill within a few years?
They do talk about those audio books that can instruct your unconscious, sleeping mind...
"Everyone else may be an a**hole, but I'm not!" - Harlan Ellison