Hope you don't mind me adding some ones I thought might be amusing.
- Randomly shout, "Man, I bet this never happened to Doctor Who!" every 10 minuets.
- Continuously claim that there’s a corpse under your seat when the army of the dead appear.
- Play with fireworks.
- In the middle of the film stand up and announce, "This isn't the super market!" and storm out.
- Bring a ring and pretend to be invisible. Go around poking people saying "ooohhh! You can't see me!" They'll probably find it really funny.
- Let a balloon fly around the room so that it makes embarrassing noises during an Aragorn and Arwen scene.
- Make shadow puppets of giant rabbits during the battle of Pelenor field, and shout "Look out, Théoden! It's going to eat you!"
- Shout "May the Force be with you!" randomly.
That’s all I have at the moment.