Here's a random thought, and I'm sorry that it involves Nikki & Paulo. Remember them? Anyhoo...
They stole $8 million in diamonds from a TV producer in Australia. They then, of course, were on flight 815. As we all remember they were buried alive mistakenly, and Sawyer dumped the diamonds in the grave. Earlier Sawyer had found a walkie-talkie in their tent. Where did that come from?
In last night's episode, it was questioned how Ben could come up with the $3.2 million to pay off the psychic dude. Said psychic dude called him "extremely resourceful", or something to that effect. Is it possible that N&P were actually "Others" who were sent from the island to steal the diamonds, and Ben then obviously knows that the diamonds are on the island somewhere and could be used to save his life?
This theory, that they were Others, is pretty thin, but it would explain:
1. Why they had the walkie-talkie
2. Why they were essentially unnoticed for a long time
3. Paulo either knew that the bathroom where he hid the diamonds worked, or at least where it was
I think, really, that I'm just trying to justify the writers coming up with such an unnecessary episode.