Aang chooses Momo as the name for his pet lemur after it steals a peach from Sokka. This is appropriate as momo is the Japanese word for "peach."
In The Art of the Animated Series, it says that the Northern and Southern Air Temples were run by monks and that the Eastern and Western Air Temples were run by nuns.
All Dalai Lamas except for the first Dalai Lama have used the last name "Gyatso." This is where Monk Gyatso's name comes from.
The Fire Temple is based on the Yellow Crane Tower in Wuhan, China.
This includes the only title card to appear not over a white screen.