possible SPOILERS---

okay il try and make it a little simpler..

Basically the Lost characters are on the island to repopulate the planet cos the humanrace is soon to be destroyed by a polar reversal. The humanrace would die because of radiation from the sun. 

The company , Dharma, has built a small 'world' on the planet by creating a 'fake' magnetic field. This means the 'survivors' would be safe from the radiation.

The button pressing in the hatch is basically there just to give the 'survivors' something to live for and to stay focused ,so it doesnt turn into a Lord of the Flies situation.

The comapany has mastered ' collective consciousness ' ,' remote viewing' and 'electromagnetism'  They can read minds as well as manipulate iron and other conductive material.
The 'smoke monster' is infact  magnetically charged iron that serves some purpose in controling the 'survivors'.

"Claire wondered why there was not one comb or hairbrush on the entire plane; the reason: the slight electrostatic charges that hairbrushing creates is interference for the collective consciousness. " ......this seems to backup the point that the island is 'made' so that the survivors can be controlled thro these means.

Theres many other things like Sayid talkin about the weird tidal movements and the fact that the North on the compasses has disapeared.

Theres SO much more but im gettin a headache by it all

PS. Think of the ' Big Brother ' show and how they can manipulate the contestents..... Lost is very simlar except on a much bigger/ important / sci fi scale

I posted that guys theory because It has alot of potential and I think its probably on the right track.

HOWEVER If it is a colony to restart the human race, then What are the Others doing there, and why are they causing problems?

Maybe the "incident" that is refered too on the cinefilm Is something to do with a previous colony they tried to set up and some catastrophe happened.

The thing with the children is bizarre too.  In the hatch there are poster paints next to a wall covered in childrens art.  So kids have been on the island before, so where are they now?
Is a Lord of the Flies thing kinda going on here? The children being the now grown up "others" who are running wild in the island.

Also another spin on it.... Desmond told Locke to find the film behind "Turn of the Screw" by Henry James.  I looked this book up on the Net and strangely its about ghosts and the children in the story are the ones who are communicated too by the ghosts.

Oh dear my head hurts LOL