So I went back to season 1 and started re-watching it after the amazing Desmond episode where we learn that consciousness is the all important means of traveling between the two timelines, at least it was for Desmond. We saw in that episode that several things can cause this shift of consciousness an electromagnetic surge, physical contact with someone you love ( or maybe just someone you had a strong connection with in the other timeline ), recreating something that happened in the other timeline ( when Charlie shows his hand to Desmond in the car underwater ), or a near death experience ( Charlie almost dying on the plain ).
My immediate thought was, how early could this consciousness shift have happened on the island and we just missed it. After watching the Pilot again I had the feeling that Jack may have experienced this shift of consciousness in the opening scene. Think about this, the plane wrecks and everyone on the plane either dies in the crash or ends up on the beach, but Jack wakes up a good 1-2 minutes deep in the jungle off the beach with only a few scratches. Then Jack tells the story of the plane crashing on the beach ( where he uses the leaf model of the airplane by the fire ) and he says after the turbulence hit and the tail section broke off, "I blacked out", or lost consciousness. I'm not sure what this means exactly, but it does look as if Jack may turn out to be the new Jacob, maybe in the finale ( or sooner ) we'll see a new scene on the island after the crash where during his blackout he talked with Jacob in the jungle.
Another thing I noticed was Vincent. When Jack wakes up Vincent is right next to him. When Jack, Kate, and Charlie trek to the cockpit the camera pans out to show Vincent in the bushes watching them, just sitting there watching them intently... This scene played out kinda creepy if you start thinking about it. How likely is it that Vincent ( who would have been in the cargo hold ) survived the crash? What if Vincent died and the MIB or Jacob used Vincent's body as a means of spying on the survivor's camp. If you start thinking about it Vincent would be an easy means for spying on the camp's survivors and Vincent was Walt's dog who is arguably one of the most mysteriously powerful season 1 characters.
One last thing I noticed in the Walkabout episode was that the machine Locke does all his work on in the office, makes the same exact ticking noise when he enters numbers into it that the smoke monster makes when it's around. Go back and watch this episode, and watch how creepy Locke is in that episode. Maybe the MIB has had Locke under his control for a while.....