Nearly every member of the military (Mustang, Hawkeye, Fury, Havoc, Hughes, and even Riza's dog, Black Hayate) is named after some type of mid-20th century military aircraft. Most of them are WWII-era airplanes. The exception to the aircraft rule is Bradley, who seems to be named after a modern APC, which was named after WW2 General Omar Bradley.
The "introduction to alchemy" book in the 3rd episode is actually a dungeons and dragons book with a transmutation circle in it.
Wrath is unique among the Humunculi because his own body was used for his transmutation; so he can never be weakened in the same way of the other Humunculi aside from making him use up the red stones in his body.
Dante's name in Latin means "Everlasting".
Within the military, State Alchemists carry ranks equivelant to Majors and can be promoted from there up.