What did Desmond say to Jack in the stadium? About why he was trainiing? I think he said something to the effect of "training to race around the world" or something. Any significance to that? He also said that he "almost went to med school" or something.
Those injections struck me as a booster of some sorts... hence the quarantine?
Also, I didn't notice for sure but was the word "quarantine" on the inside or the outside of the hatch? Because if it were on the outside, you would have thunk that Locke, Boone, Jack or Sayeed would have noticed that in the first season. If the "quarantine" were actually on the inside of the hatch, that would raise an interesting scenario..
As far as the sunlight down in the hatch goes, I have one possible explanation: mirrors.
Desmond had set up mirrors to shine the light outside the hatch, he could just as easily have another hatch with which to direct sunlight into his habitat. Maybe? Heh, dunno.. sounds good though.
For some reason also, I felt when watching Jack's flashbacks that they were taking place 5-10 years ago.
Wow. Lots of random thoughts..
EDIT: Also, there's that period when Jack was examining what sounded like a generator and the key around his neck was attracted to that direction. What kind of power sources generate magnetic fields that strong?
And finally, did anyone catch what Walt was saying to Shannon? I couldn't really tell.. and that scene was really freaky by the way.
