What can I say? Best episode ever. Desmond's and Penny's story is one of the most touching love stories ever. The phonecall is probably the most emotionally moving scene of this show to date. The back and forth scene changing was so intense and so great... I can't praise Jack Bender and the episode editors enough for this.
The whole episode was an excellent, and I mean EXCELLENT mixature of human emotions, character development, and that typical Lost confusion that makes you go "wtf" all the time.
This episode overtook Flashes Before Your Eyes in my books. Perhaps because this episode covered much more ground than FBYE. It's funny that, if you look at it, there was barely any action, and the whole episode took place in very limited locations, yet it feels incredibly fast paced and action packed. Daniel's character is further explored, and now he's officially my favourite frightie, although Frank is very cool too, he seems like a good person. But Daniel... he's borderline genius and crazy, and that's just awesome. The ending... Desmond being his constant? Wow. Well... makes sense, but I didn't see that one coming, even though I should have. Obviously, Desmond was very important to Dan, because through him, he finally proved the existance of time travel. I never thought I would write that down in a review of a Lost episode... wow.
I'm somewhat speecheless right now, so excuse me for the sloppy and short review. This episode hit perfection, and there's barely any TV episode that can put up a fight with The Constant.
Maximum respect to the cast and crew.