Uncle Vernon: And Dudley, you will be?
Dudley Dursley: I'll be waiting to open the door.
Uncle Vernon: Excellent. And you?
Harry: I'll be in my bedroom, making no noise and pretending that I don't exist.
At the beginning of the scene near the end of the movie with Lucius Malfoy fuming at Dumbledore in his office, Malfoy's hair is fanned back behind his shoulders. The lighting in the room illuminates the back of his neck, where you can see his real, short brown hair.
In the scene where Harry and Malfoy are flying on their brooms, there's a shot where Colin takes a picture. Listen to the music right after that. The music is the same music used in Star Wars: Episode II - Attack of the Clones during the chase scene on Coruscant (John Williams did the music for this film and all the Star Wars films).