Finally we are seeing what this weird guy is about who smiles at people with oranges in his mouth. It turns out this episode doesn't make him look any more sane. This has always been one of my favorite episodes though. It's pivotal to all following seasons, and it sets up what this show is all about overall. I don't think it's any coincidence that the question of faith begins to be presented in this episode along with Locke's surprise ending.
Besides Locke's story line there isn't anything that really stands out about this episode, which is probably the complete intention. We have the issue of people's faith on the island brought up at the beginning when we can see some obvious upset emotions from Sayid about how the dead are being treated, and then we quickly get into learning about Locke from there. We see a flashback that helps parallel a lot with how Locke is on the island.
The monster also appears again in this episode, and Locke certainly gets a look at him that we aren't able to see. While Kate, and Michael huddle in fear in a tree, Locke instead seems to stand in awe of whatever this creature is, which raises some questions for the viewer. Also, we have the appearance of the warthogs, which for now probably don't speak much, but it will in the future! They do attack Michael though, and cause Locke an upset.
The flashbacks seem pretty pointless until right up to the end, which is how I think the creators of the show were able to bring the biggest shock that we've seen in four episodes, that Locke couldn't walk prior to crashing on the island. When I discovered this I felt like I had found the greatest twist ever because I wouldn't have ever guessed it. Even though when you go back and watch the show over it is so obvious in the flashbacks. So this is by far one of the most significant episodes ever in the history of Lost. It sets up so much that will last through all the seasons.
Why can Locke walk now that he is on the island?
Why was Locke paralyzed in the first place?
Who is Jack seeing at the end of the episode?
What did Locke see when he found the monster?