Now first of all, I'm not even going to try and come up with a semi-logical or rational theory as to who/what Jacob is. However it seems rather obvious that all the "Others" look to Jacob as some sort of messiah and/or great leader... yet for one unexplained as of yet reason, not just anyone can even find his cabin, let alone speak with Jacob. I figure that only someone "special" can see him, and Richard's job is to find this "special" person, so that the Others may communicate with their leader, Jacob. Now my theory here is that Ben was supposed to be this special someone, yet experiences in his life have caused him to become corrupt, egotistical, and too focused on "trivial things like fertility" and it seems at least some of the others are quite aware of this. Now, up until Locke arrived on the island, Richard and the Others tolerated Ben's actions as a means to an end... No Ben, no Jacob. Now, with Locke's arrival, the Others want him to take Ben's place, they think (or know) that Locke will be everything Ben was supposed to be, and more. Now at first to save face, Ben pretended to help Locke in front of his people, but did everything in his power to impede Locke any other time. Ben, due to his ego is still convinced he is the special one, the chosen one, so to speak. Thus, he is doing everything Locke is "supposed" to be doing... Turning the wheel, getting the O6 together... not to mention multiple attempts on Locke's Life (and finally succeeding.) He's doing everything he can possibly think of to convince the Others and maybe Jacob, that it is he who is supposed to lead the Others... not Locke. Now I love Ben and I hate to think of him as this corrupt, evil tyrant... but the more and more the show goes on, the more it seems that way. Furthermore... this could very well be the reason Ben had Widmore banished. He was either a threat to Ben and his plans, or he really was corrupt... Ben ultimately became the very thing he fought against when he was younger.
I dunno... just some thoughts, this week off is gonna kill me... not to mention it doesn't look like they're gonna touch the Locke/Ben side of the story for at least one more episode. Not a big deal though... this DHARMA stuff is fun!