Re Jacob's Ladder:

Folks may or may not recall that in "The Long Con" Locke was looking through "Occurrence at Owl Creek Bridge" aka "The Incident at Owl Creek Bridge" by Ambrose Bierce. This story received a modern adaptation in the movie "Jacob's ladder" with Tim Robbins. Actually it has been borrowed from in quite a few later works:
http://en.wikipedia.org/wiki/An_Occurrence_at_Owl_Creek_Bridge

In the original story, a whole sequence of experience takes place and appears to be real but at the end you find out it was just what flashed through the man's mind as he was hung in that split second that he was dropping before the rope broke his neck.

In the Robbins movie, most of the experiences turn out to be his dying moments.

I know that Darlton went on record saying that Purgatory is not the answer, and the Losties are not dead. They also promised that they're not in a snowglobe. But they have put an awful lot of Easter Eggs out pointing to Owl Creek and Jacob's Ladder, named after the ladder by which you ascend into Heaven. (Jacob had that vision as he was running from his brother Esau). They made a huge deal about The Third Policeman, which is another book that takes the theme of Owl Creek, giving it an Irish twist.

And Gary Troup's name is on that wall twice. (Gary Troup = Purgatory). So the Losties aren't dead, but is it possible that some of their experiences are taking place in a "flash" moment that is between life and death? We have an episode called Flashes Before Your Eyes, we have Flash Backs, Forwards, and Sideways.

Here's a line from the Third Policeman that might be worth thinking about as well:

"Joe had been explaining things in the meantime. He said it was again the beginning of the unfinished, the re-discovery of the familiar, the re-experience of the already suffered, the fresh forgetting of the unremembered. Hell goes round and round. In shape it is circular and by nature it is interminable, repetitive and very nearly unbearable"

In Third Policeman, the character finds out he is dead and in hell, and that hell is a loop, and that is the ultimate torture, to go round and round having the same experiences, but not quite remembering that you've done it before.