Alright heres my theory on the group of losties who are traveling through time on the Island. Let us assume that Daniel Faraday (with the exception of Desmond) is true about what he said about time travel, you cannot change the past.

Now if we take that into consideration and also the possibility that the TT.Losties might one day accidently travel back in time to a location that they werent seen in in past seasons, that they might actualy become the infamous whispers that we have heard throughout the series.

Lets say that in a future episode of this season that the group travels to a point in which we heard the whispers in past seasons, either when Sawyer was in the jungle hearing them, Ana Lucia, Shannon, etc.

Now because they dont remember seing the TT.Losties in those instances then they cant and arent supposed to see them, so to compensate for this, they are able to hear them. The whole "I can see eye to eye" could simply be reffering to somebody literally staring eye to eye in front of them and they are non the wiser.

I dont wish to debate whose voices we hear during those scenes, the Island could be manipulating the people there or simply ... something happens in which those people had to be there. I dont know.

I like where you're going with this. The idea of the Island manipulating the voices leads me to think that it made the voices appear as something familiar to those who'd be hearing them.

Alright heres my theory on the group of losties who are traveling through time on the Island. Let us assume that Daniel Faraday (with the exception of Desmond) is true about what he said about time travel, you cannot change the past.
I'll take that as trivially true without time travel.

Now if we take that into consideration and also the possibility that the TT.Losties might one day accidently travel back in time to a location that they werent seen in in past seasons, that they might actualy become the infamous whispers that we have heard throughout the series.
I'm sure that that's exactly what they're going to say was the case. And they'll be right -- they and/or unseen cohorts were whispering to each other. Only they didn't have to travel in time to do so. And they didn't.

Robert in the Bronx

From the looks of next weeks previews for episode 4, it seems that they travel back in time to when we see Kate witness the whispers, and when Boone is sacrificed to the island. (2 time jumps?)

Did we hear the whispers soon after Desmond turns the light on in the hatch for Lock in season 1? I cant remember. That would be towards the season finale of S1. Will the smoke monster try to capture Lock again?

If we are to assume that each time jump represents a mission from the Island to the TT.Losties (Lock needs to get shot, Daniel needs to send a message to Desmond, Lock needs to make contact with Richard...etc). Could the island be giving them a mission to talk to the past losties through whispers?

Sawyer says in the previews "I just saw Kate!"

*edit le spoiler tag

:Welcome: Welcome to the Lage, Lolzst. I also think that the whispers may be the voices of those who are "lost" in time.

P.S. please spoiler-font information about the previews for those of us who want to remain spoiler-free ;).