Did anyone else notice..
 

That Neytiri has her knife strapped on her belt during the mating scene with Jake?

I thought that was interesting. Neytiri seemed to be armed at all times in the movie.

I did notice that. I also noticed that when Neytiri was training Jake up, we see him without a knife across his chest, with a knife in one scene, and then no knife until Iknimaya. It makes me sad to find a continuity error :(

Probably in case a Thanator or Hammerhead unknowingly walked in on them
;)
In a way, I feel sorry for them if they did..

... that Na'vi carry their weapons behind, but Jake carries his up front because that's where his Marine-issue Ka-Bar would be?

They are not a warlike race. They have "warriors" but really, what do they do? surely not raid and pillage other clans??? I'm guessing they spar. Surely they aren't trained in hard core hand-to-hand like Jake was. He totally pwned Tsu'tey after the mating scene, unarmed and un-pissed. 'Ooo-rah!

He sure did, that was awesome!

well Jake is part of the Jarhead Clan... they probably like to switch it up

...that the ship controls were on the right instead of the left?

I noticed that, but I didn't notice that that was strange. I'm not an aircraft aficionado. :P

I noticed Neytiri's knife. I really doubt she'd go anywhere without one though.

Seamus, your sig is SCARY! O_o

Given the conditions on Pandora, once you have become an adult, you never go anywhere without a weapon to defend yourself. Indians did the same thing, it's self protection against nature not each other.
I found it irritating also that Jake's knife is thrown down in Hometree, he gets it back after he wakes up and loses it then finds it again.
Also..someone had to find Tsu'tey's body and retrieve the clanhead neckpiece for Jake to wear.
As for the knife position, it could be personal preference..where did Tsu'tey wear his? I think it was in front. I don't think Jake had his in front because of his previous experience..in the scene where he's carving the stick to a point... and later when Tsu'tey trips him with the bolas, I think he pulls his knife from his belt. (Have to watch it for the umpteenth time to see that.)

Tsu'tey had his knife at his waist, as did Jake with his knife before he becomes Na'vi.

As for him losing it, I assumed Neytiri got it when she took his body off after the link was lost, and put it back then. He lost it when Hometree was destroyed, but I'm sure someone gave him a new one when he arrived as Toruk Makto...

Needed to resurrect this thread because I noticed something when I saw the SE in the theater.
When Jake is running along the shuttle to jump off, Toruk turns his head up and roars at him like a greeting! I thought that was totally cool! It was like he was saying,
'Hurry up man! I almost left you behind!'
Also, when he jumped off Toruk, the beast angles away really sharp, so it's even more cool that it effectively was keeping an eye on his progress and timing his speed and position to Jakes.
That's tsaheylu for you, Jake thought the whole thing in his head, letting Toruk know what he was going to do.

Freaking amazing stuff!
(Going to see it again this weekend for the second and likely last time in the theater. Going to be fuuuun!)

Toruk are certainly intelligent too, I think :)

It's not necessarily a continuation error. As Jake was there for 30 days and we only see a few moments. Anything can have happened between what we see.