(If this is already being discussed in another thread, I apologize.)

Does anyone else think that maybe the reason Locke had such a hard time finding Jacob's cabin was because it moves through time and/or space also?

I think the show used the concept of the Cabin's ability to move to prepare the audience for moving the island. The same way that FBYE and The Constant prepared us for an all out island time-shift dance party. You can't just throw these big concept meals out there without an appetizer first.