Message in a Battle
The WP has a tale titled The Messages in a Battle about the recent growth of computer-generated battle scenes in movies, now that you don't have to pay all those extras. RotK clearly wouldn't have been much of a movie if the battle scenes hadn't been so good.
Personally, I think Gollum was utterly believable within the scope of LOTR. OK, not human - but the interaction with surroundings, the characterisation, all seemed pretty much perfect.
Dobby the House Elf in Harry Potter was ground-breaking, but Gollum seems to be a whole generation above that.
I say we take off and nuke it from orbit. It's the only way to be sure...