The Dark Tower is the series of gunslinger books by Stephen King. The LOST crew also had a copy of The Stand on the table for a lot of their brainstorming sessions. Check out this link:

http://www.lostpedia.com/wiki/Stephen_king

There are spoilers there if you haven't read those SK books, but you can tell there's a lot of parallels going on there. The guys from LOST just took it and ran! On a side note, SK sold the movie rights to the Dark Tower series to JJ Abrams for 19 dollars - one of the "numbers" in the Dark Tower series.

I wish February would hurry up and get here!