Now, I am not positive about this, but somewhere I think I read that you should never keep any chocolate in your *checked* luggage. It was something about confusing the drug sniffing dogs. Any bags with chocolate in them have a bigger chance of being searched.
I brought some snacks in my carry-on like those little boxes of graham crackers, small baggies of chocolate chip cookies, and the old fashioned animal crackers. You should bring a zip-lock baggie to put in the left overs.
When I didn't eat the full box, I folded down the wax paper carefully, and every time my snacks were very stale by the next morning. I think it was something about the humidity in the room. I try to always bring a few envelopes of instant oatmeal, because that is my late night snack.
Every year, I always seem to bring too many snacks, though, and take most home with me.