Artifact Title: Most of the movie takes place in Los Angeles, but it's all set into motion by The Job they did in Italy.
Artistic License - Physics: During the planning stages, the crew decides on using MINI Coopers because they fit in the hallways of Steve's house. The cars would fit, but they certainly wouldn't be able to turn the 90 degree corners.
Boring Insult: Steve is accused of having no imagination after stealing the gold, having spent it on all the things everyone else had wanted.
Cable Guy Infiltration: After the men recruit Stella, they set up a plan to infiltrate Steve's house. Handsome Rob first steals a cable company van by flirting with one of their employees, while Left Ear tampers with the cable box so that Steve's TV and modem will not work and Steve will be forced to call to set up an appointment. Stella is used as the infiltrator because Steve doesn't know what she looks like. Using the phony name "Becky", she wears a mini-video camera disguised as a flag pin to allow the men to map up the house layout.
Cameo: Well, not quite. Steve is watching The Italian Job on DVD, but all we ever see is a part of Michael Caine so they wouldn't have to pay royalties by showing his face.
Also, that really was the creator of Napster playing himself stealing the idea from Lyle in college.
Fruit Boat: During the opening heist, a pursuing boat accidentally drives up another boat, is launched into the ear, and lands in one.
Gag Dub: Lyle (Seth Green) does this while Handsome Rob (Jason Statham) chats up a young girl with the aim of seducing her and getting her ID card. Bonus points in that Seth Green improv'd his dialogue.
He Knows Too Much: Yevhen, while rambling about gold usage throughout history, stumbles upon the source of the gold Steve's been fencing through his shop. Steve kills him for it. Unfortunately, Yevhen is part of a local Ukrainian crime syndicate, which comes back to bite everyone later.
Helicopter Blender: Steve attempts this against Charlie, who's in a Mini, using the tail rotor. Charlie just barely manages to scrape by, but the rotor is ruined by the attempt and the helicopter is grounded, forcing Steve to jack a car to continue the chase.
Historical In-Joke: Lyle was the real inventor of Napster, but Shawn Fanning was his roommate and stole his idea while he was napping at his computer
Hollywood Density: Discussed Trope. They have to specially modify the cars to be able to handle the weight of the gold. Also, when the gold is being taken out of Steve's mansion, Lyle is able to figure out which of the three armored cars contains the gold because it's riding significantly lower than the decoys because of the weight of $27 million in gold bricks.
Instant Seduction: Handsome Rob flirting with a cable girl so he can get her shirt and her truck to give to Stella so she can infiltrate Steve's house. Lyle trying to get an idea of what the conversation's going like supplies the page quote.
Model Planning: The thieves build a replica practice course in a warehouse to practice driving their escape route, and also have a CGI animation on their computer of the car as if it were traversing the actual route in real time for no apparent reason.
Money, Dear Boy: Edward Norton made no secret he was forced to do this film as a contractual requirement with Paramount. He had signed a three-film deal with them, the first of which was Primal Fear, but kept passing on scripts for the other two films until Paramount basically threatened to sue him unless he fulfilled his obligation to the studio. Accordingly, he refused to promote the film.
Turn In Your Badge: Parodied. Handsome Rob, whilst trying to drive through the city as fast as possible to time the fastest possible escape route, is the second car in line stopped in the left turn lane at a red traffic light (note, this is a green arrow only turn signal). Unfortunately, the driver in front of him is an actor rehearsing the phrase, "Give me your badge and your weapon; I don't want to see you anywhere near this case (pretends to crush cup)" in such a variety of different voices and emphases while reading off the script itself he fails to notice there's a green arrow, until the very last second when it's turning amber and Rob starts shouting "Hey! It's a green!" and honking at him, so he's the only one that gets to go through, with a very disgruntled Rob saying, "Unbelievable!" in disbelief. Also, bonus if you noticed that the actor copies Rob's accent and decides to use that accent for the audition.