I spotted something very strange while Sayid was approaching the beach in the Zodiac. What looks like a large non moving turtle is sitting maybe 20 feet from the edge of the water. It's only in about 3 secs worth of frame and another camera angle shows a completely different beach (footprints).
Now I might be really picking this apart but there may be some relevance to a turtle on the island. Not to mention bears.
In the Dark Tower series by Stephen King, the heroes travel along a path called the Beam. It's a invisible, yet noticeable, flow of energy from one point of the world to the center. On the opposite side of this center is another Beam coming from the completely opposite direction. There are 6 sets of these Beams that form the foundation that the universe rests upon. The Heroes start along this path by slaying a giant bear with a gun. This bear was the guardian of the path of the Beam and was infested with disease and neglect (it was a cyborg). While the Heroes never traveled the path of the Turtle, which lies opposite the path of the Bear, they did receive an idol of a turtle that had great powers.
With the impending moving of the Island and the sudden appearance of a turtle on screen, I expect our Heroes to start traveling a much different path then the one they were on before. Things are about to change drastically. The Heroes still travel the path of the Beam, towards the center of power, but are just approaching from the opposite angle.
The paths of the 12 Beams are powerful enough to bind and hold together parallel dimensions that all revolve around the Dark Tower, center of the universe. These parallel dimensions are very well what could make "moving the Island" very unpredictable. Who knows how different another path would be from the one we are already traveling. What would they need to sacrifice and who will get left behind? What conflicts will arise because people are out of place?
During the movement of the Island I would expect those contained on it to be unaware of anything happening. However things would happen, "course correcting" to eventually return everything to it's proper balance and purpose. And so ends the Human race.
The failsafe key might have done something very similar to moving the Island.
I haven't read the Dark Tower series, but when I watched the episode, I remembered wondering if that thing on the beach was a turtle. We couldn't see it from any other angle. Interesting info about the turtle's role in the DT series.
According to what I've read, those turtles are a highly protected species - so if one is in the path of the camera shot, they basically just have to deal with it.
Per Lostpedia:
"Several large sea turtles can be seen on the daytime beach shots. As the turtles are heavily protected by the government, it is likely that the crew was unable to remove the turtles from the shots before filming."
So don't get too excited. The presence of the turtles was likely completely incidental.
I can't find any info about sea turtles on Lostpedia. Which other episodes had turtles visible? Did those episode relate to time/space travel?
I can certainly understand that they are not filming in a studio and things aren't entirely in their control. However I expect that the post production and editing is rather extensive and an obvious turtle disappearing from one cut to another is a bit lazy. They could have CG'd the turtle out of the 3 seconds of film. It is only a TV show though ...
Perhaps they're just celebrating the natural life on the Hawaiian Islands with 3 seconds of screen time.
I was originally going to say that the turtle didn't mix well with the background and that it was a CG turtle. However with the obvious presence of turtles on the Islands of Hawaii. I just assumed the odd image was because the camera was on the waves and the movement made it look strange.