21 Grams (2003)
The moment where Naomi Watts's character is in the swimming pool, curled up, holding her head underwater is an artistic tribute to the bathtub scene from Satoshi Kon's Perfect Blue where the main character submerges herself in the bathtub.
There are two moments it references PI, from Darren Aronofsky. At the moment Paul and Christina are having lunch and he starts to talk about Mathemathics in everything around, coming to a superior stuff, and a few seconds later, when the cam aims to the Sun, just like did Max Cohen (Sean Gullette's character in PI).
When Jack Jordan (Benicio Del Toro) comes back after his period in jail, his daughter is painting on the floor, and close to her there's Heimlich , the caterpillar of A Bug's Life.
A Slinky Dog toy is shown.
Naomi Watts' chracter, Cristina, mimicks the pool scene in which Julie goes into a fetal position (and also the fact that she has lost a husband and two daughters--instead of Julie's one--in a "car" accident).
Jarl mentions the film
Subject of a $1,200 clue in the category "Movie Number, Please"
referenced in clue and correct response in "Movie Numbers" category
Relatives and/or victims of an accident get together,
A "21 Grams" movie poster can be seen.
making of the movie
Style of editing inside of apartment buildings is directly influenced by "21 Grams", as stated by the director.
Featurette about the making of the film