Not really sure if there is a thread dedicated to this but im having trouble understanding how did Ben know about airplane landing in S5 on the smaller island and him coming back to the island. We know he was building a runway in S2 with Kate and Sawyer hauling rocks back and forth. So i guess what im wondering is does anybody have general idea on this, can he see the future like Desmond or something to that extent, or the theory that makes more sense that he might have been through all of this before( we know he is almost allways a step ahead of his opponents and allways has a plan)?

I'm going to go with:
1. Someone we know is from even further in the future and has traveled back in time to the present (or slight past). This person has met with both Widmore (there is a war coming) and Ben (build the runway). Of course, this person is keeping quite because he/she has his/her own agenda in the future. The big reveal is that this person came back through time and is setting everyone up.
or
2. Someone we know is a seer, probably Ms. Hawkings. She has visions of the future and is guiding everyone to play their parts, (just like she did Des) to ensure that things turn out the way they should. The big reveal would be an unseen glitch in her plan.
or
3. Jacob is somehow omniscient and is guiding things. I don't know enough about Jacob to speculate.