Anachronic Order: The film starts with Wilee getting tossed off his bike after hitting a cab, then keeps shifting between points in the day to show the individual activities of the various characters before coming together in the climax.
Awesomeness by Analysis: One of Wilee's special abilities is a Sherlock Holmes-like analysis of routes ahead when maneuvering gets tricky, where many hypothetical scenarios are acted out in his head.
Bavarian Fire Drill: Subverted. Whenever Monday presents himself as anything other than NYPD the person being conned either sees straight through it (in Nima's case) or refuses his demands (in Wilee's case).
Betty and Veronica Switch: While it starts off with Manny being the reliable guy who drives Vanessa around and (rightfully) points out how dangerous Wilee's riding is, Manny is further revealed to be a Jerkass and Wilee doesn't hesitate for a second to help Nima out once he realizes it's her kid on the line.
Beware the Quiet Ones: Sudoku Man never says a word. He just sits around, finishing sudoku puzzles. It turns out that he conceals a small pistol with his sudoku book, which he uses to kill Det. Monday.
Black Comedy: The "bad result" predictions Wilee makes while dodging traffic get increasingly ridiculous, ranging from things like running over a baby to getting hit by three different cars.
Boom, Headshot: Averted. Monday takes a while to realize he got shot in the head, and is pretty much normal for about a minute until he begins to stumble and dies.
Brick Joke: Wilee tries (and fails) to steal a kiss from his ex Vanessa. He points that she still arches her neck. Later, when Manny steals a kiss, her neck doesn't move and she rejects Manny almost immediately.
Bullying a Dragon: Monday insists on being belligerent to the Chinese gangsters at least half the time, and this is especially bad because he clearly realizes that being a cop is not enough to protect him.
Bystander Syndrome: Within New York's Friendly Local Chinatowns, Bobby has relatively free rein to dish out violent intimidation while the rest of the public look on. Justified as it's implied that a large proportion of the population are illegal immigrants who refuse to bring attention on themselves, as well as being cowed into non-activity by the men running the Chinese gambling dens. Unfortunately for him, that door swings both ways.
The Cavalry: For the climax, Raj rallies a flash mob for Wilee consisting of every nearby bike messenger from every company in the city.
Chain Pain: In the opening, Vanessa uses her bike lock chain to knock off a cab's driver's side mirror, in retaliation for nearly running into her during a lane change.
The Chew Toy: That poor bike-patrol officer. Every time he tries to give chase to the protagonist, he always ends up slightly more injured up than before, until he quits at the end of the movie. Even though Wilee is being forced to evade Monday's increasingly deranged attempts to get his cargo, Wilee is still breaking traffic laws and putting himself and those around him in danger, including pedaling into oncoming traffic.
Vanessa: That was the most fun I've ever had with my clothes on!
Even Evil Has Standards: When stealing the ticket is first suggested as a way to cover his debts, Monday rejects it out of hand, citing the fact that he's a cop, not a mugger. Subverted when his temper lands him in hot water and he realizes it's the only option left to him.
Hair-Trigger Temper: NYPD officer and antagonist, Bobby Monday, whose Pai Gow addiction and temper have gotten him in deep with Chinatown gamblers. He even outright tells Nima he's been diagnosed as such. For instance, after one of Mr. Lin's enforcers knocks out one of his teeth, Monday smashes his face into a truck grill, causing fatal injuries. The enforcers were simply roughing him up for losing all his money that he borrowed for another gambling trip. This becomes the impetus for his later downfall.
It's All About Me: During their ride in the ambulance, Monday tells Wilee that his problems are more important than the fate of Nima's kid, and even has the nerve to act like it's her fault that he's trying to steal her hard-earned money to cover his own idiotic decisions.
Jerkass: Monday and Manny, though the later is merely an off-putting jerk instead of a sociopath.
Karmic Death: Monday boasts that he could murder Wilee in public while in the middle of a Chinatown slum, and no one would testify against him. Chinese gangsters murder Monday not long after, and no one bats an eyelash.
MacGuffin: The ticket. It's a voucher for $50,000 to pay for the illegal immigration of Nima's son and mother.
Magic Countdown: It's a bit difficult to believe that Wilee could chase down Manny, get into a cross-town race to the wrong address, end up at the hospital for however long it takes to get his arm bandaged from the crash, get driven to the police impound, then ride all the way to the right address within 40 minutes.
Major Injury Underreaction: Monday takes a while to even realize he just got a bullet to the head, and is almost disturbingly serene until he drops.
Mood Whiplash: As funny and self aware the movie is, there are several instances, mostly involving Bobby Monday, where it gets shockingly dark.
Police Brutality: NYPD officer Bobby Monday liberally dishes this out on anyone who crosses him. Other officers, however, are only doing their jobs, including the irritated bike cop who tries but fails every time to reprimand Wilee when he breaks traffic laws trying to escape from Monday.
Politically Incorrect Villain: Bobby Monday refers to Nima with the racial slur "slope" in the back of the ambulance with Wilee. Later, right before taking a fatal bullet to the back of his head, he issues a threat containing the word "zipperheads" directed at a crowd of Chinese gangsters.
Rage Quit: That poor bike cop has had enough of Wilee's antics once Wilee steals his police bicycle.
Real Time: Not exactly. While the film frequently uses Anachronic Order to get the job done, the bulk of the film (and the film itself) takes 93 minutes, start to finish.
The Resenter: In the background at the party where Wilee is kissing his hot girlfriend and winning a fantastic bike for being the best bike messenger for three years in a row, Manny is sitting with a beer and silently fuming.
The Reveal: The envelope contains a $50,000 ticket for Nima's son and mother aboard a ship that smuggles people from China to America.
Running Gag: Wilee trying to get something to eat, but stuff always happens to prevent him from doing so.
Screw This, I'm Outta Here!: After a couple humiliating and painful encounters with Wilee, the bike-patrol officer finally has his bike stolen by said bike messenger. His response to this theft of police property? "You know what? I'm done."
To Looney Tunes of all things. Wilee (Wile-E) is sometimes called "the coyote man," a character seen for a moment is called Roadrunner, and Detective Monday is more or less doing an impersonation of an evil, less resourceful Bugs Bunny. Bugs always lost when he was the aggressor, after all.
Whenever Monday needs a pseudonym, he goes with the name of sci-fi fandom fixture Forrest J. Ackerman.
Smug Snake: A smirking, self-satisfied Big Bad Wannabe, Officer Monday equates being a dirty cop with being an unbeatable Badass, even in situations where he is clearly at a disadvantage (like being surrounded by Chinese gangsters intent on killing him).
Stock Scream: During one of Wilee's split second hypothetical scenarios while pedaling towards a busy intersection, he images himself running over an unfortunate pedestrian who is then flattened by an oncoming vehicle, letting out a Wilhelm Scream.
Suspect Is Hatless: The bike cop can only manage to narrow Wilee's description down to "red shirt, beat-up bike". Surprisingly, this alone is enough for the other cops to accurately peg Wilee so the bike cop can resume his chase.
Title Drop: When Raj gets Nima's call and he and Wilee fight over who's taking the drop:
Wilee: Come on man, I'm tired, I'm hungry, my day is taking a turn for the shitty, gimme the 40.
Raj: I'll give you 30. Don't screw it up, it's premium rush.
Think of the Children!: Monday complains about the use of bad language on primetime television to Wilee while interrogating him.
Throw the Dog a Bone: Considering the Butt Monkey status of the bike cop, he at least manages to catch one of the people he's chasing when he makes an impressive tackle of Manny. That said, he does later have to apologize for doing it since while Wilee knew the cop was coming, Manny did not.
Wilee: I do not carry drug shit, or whatever the hell this is!
Raj: It's not drugs, it can't be drugs. It's from a highly respected East Coast college. (covers phone, turns to Tito) It's probably drugs.
Unstoppable Mailman: Averted and played straight; after being pursued by Monday, Wilee decides to cancel the delivery until he realizes its importance and then goes all out with this trope.
Working with the Ex: Wilee and his ex Vanessa both work for Raj at the Security Courier Services. In fact, it is through Vanessa that her roommate Nima learns of Wilee's reputation as a bike messenger extraordinaire and decides to trust him with a very important delivery.
Wrongful Accusation Insurance: Wilee is repeatedly chased by police for moving violations, steals from a police impound, and later steals that bike cop's bike, but there's no indication he is ever prosecuted for his actions. Somewhat justified; the only cop who ever learns Wilee's nickname is Bobby, and he never even shares that. Everyone else only knows him as the bike messenger with a red shirt and a beat-up bike. They'd have a hard time even finding him, much less prosecuting him.