Not sure if it's been posted yet- but the other night we watched 'Children of Men'. While not perfect, there were atleast a few scenes (the long takes) in there where I was thinking 'my god! this is insane!' I have no idea how those shots were constructed, well.. yeah I do- computer graphical trickery! But it was extremely well done.
I got on to this film through my 3d graphics class, where we saw that the last scene where the woman gives birth, is actually done in 3d (the baby, that is). It's basically seamless.