The Marine colonel swigs from his coffee mug in the middle of a gunship attack, like Colonel Kilgore in Apocalypse Now.
There are oodles of Aliens Shout Outs. Let's just mention that Sigourney Weaver's first appearance on-screen is inside a capsule and leave it there, although to prevent one accidental similarity Cameron changed her chracter's surname to Augustine rather than the original Shipley, which he decided was too similar to Ripley. Believe it or not. Also, RDA company man Parker Selfridge is a bit more sympathetic than Weyland-Yutani company man Carter Burke.
The original Avatar Project leader (before Grace and before its focus on the Na'vi) was Dr. Cordell Lovecraft, and the project was called "Dark Dreamer". (Fun fact: Lovecraft was awarded several Nobel Peace Prizes, only to be withdrawn by protests from several groups... one of them being the UN.)