Okay, so about halfway through the finale I had to use the restroom. Whilst urinating I was struck by a cool realization: When Ben summons the monster he pulls a cork from a puddle of mud and drains it. This was on a small scale very similar to Desmond removing the island's cork and draining the, uh, 'magic water'
Just something I noticed.
Also: I found it cool that the first image we see of the flash-sideways, or afterlife if you prefer, is clouds. Which is cool cuz it brings to mind heaven and what not. I dunno, I just thought it was some cool symbolism.