I've watched it pretty regularly, Lou. Ironically, I first saw it while on the island of Oahu (where it is filmed) not long after it came on the air. (Though by now, people must think I live on Hawaii when I really don't think all that highly of the place. :undecide: )
Purgatory, eh? That's a great guess. I always thought the plot was that everyone sort of had to face their worst fears of themselves on the island. So I think we're really saying the same thing here. But I like your purgatory theory even better, as it explains why so many people survived relatively unscathed when the plane came apart with impact.
Call it "Karma Island".
There are a lot of character annoyances with the show, but overall it's still pretty addictive. I totally guessed who the "Others" really were in the last season finale. Will be interesting to see how they salvage the cast to start the next season.