A friend writes to ask me what I thought of S.O.S. overall as an episode. Truthfully, I thought it was weak, lame, and totally uncool. I can't believe this was what they left us with heading into a break. Still, there were some interesting clues about what kind of effect the Island is having on them. One was Jack's shooting skills (I don't believe he could have pulled that off in the real world). Another was Locke's memory boost as a result of leaving the Hatch.
The latter, in particular, really caught my eye. Notice how he's having trouble with recall while he's inside the Hatch. It's only after Locke leaves the Hatch that he receives inspiration, and I don't think it was just from the fresh air. Whatever the Island does to people, the Hatch acts like an insulator. It protects people from being changed by the Island before they're prepared.
These changes include enhanced strength and memory retention (both intended effects of MKULTRA/Monarch programming). This has to be of great concern to the Others, who I still believe weren't expecting our losties. At first, the former had the advantage of superior strength and senses. But that gap is rapidly diminishing the longer they stay on the Island.