Olive Penderghast, a teenage girl living in Ojai, California lies to her best friend Rhiannon Abernathy about going on a date in order to get out of camping with Rhiannon's hippie parents. Instead, she hangs around the house all weekend listening to Natasha Bedingfield's "Pocketful of Sunshine". The following Monday, pressed by Rhiannon, Olive lies about losing her virginity to a college guy. Marianne Bryant, a prissy and strictly religious Christian at their school, overhears her telling the lie and soon it spreads like wildfire. The school's conservative church group run by Marianne decides Olive will be their next project. Olive confides the truth to her friend Brandon, and he explains how others bully him because of his homosexuality. He later asks Olive to pretend to sleep with him so that he will be accepted by everyone.
In 1888, Mary Kelly (Heather Graham) and her small group of London prostitutes trudge through unrelenting daily misery. When their friend Ann Crook (Joanna Page) is kidnapped, they are drawn into a conspiracy with links higher up than they could possibly imagine. The kidnapping is soon followed by the gruesome murder of another woman, Martha Tabram (Samantha Spiro); and it becomes apparent that they are being hunted down, one by one as various prostitutes are murdered and mutilated post-mortem.
Reporter Rowena Price, under the pseudonym of David Shane (Halle Berry), and researcher Miles Haley (Giovanni Ribisi) are investigating conservative Republican senator Stephen Sachs, who has been having secret sexual encounters with his male interns, despite his publicly anti-gay agenda. The story is shut down, however, when the source clams up and Rowena's editor, a supporter of the senator, puts a stop to the story. The editor also insists she take a vacation and won't take no for an answer.
The film begins as Marcus (Eddie Murphy) enters Chantress, the company that he works for as an advertisement executive. It is quickly established that he is quite the ladies' man, as he tells his assistant to send flowers to nine different women, with cards reading "only thinking of you." When he enters his office, Nelson (Geoffrey Holder), one of the creative minds also in Marcus' department, shows Marcus a re-cut he's done of one of the ads they've been working on. Marcus tells Nelson, who's very creative but also very risqué and overtly sexual with his style, that he must re-edit the ad, as some of the material may be offensive to women and may also cause problems with the U.S. Federal Communications Commission. Nelson reluctantly agrees, then leaves.
Ed Earl (Reynolds), the sheriff of Gilbert, Texas, has a relationship of long standing with Miss Mona (Parton), who runs a brothel there called the "Chicken Coop." Illegal or not, Ed Earl doesn't interfere with her business, which has been a fixture in the town for as long as either can remember.
In an opening scene, a group of men are interviewed regarding Christina Walters (Cameron Diaz) who introduce her as a player and a user of men in the swinging singles market. The men include:
A Miami area high school guidance counselor, Sam Lombardo (Dillon), is accused of rape by two female students, the wealthy and popular Kelly Van Ryan (Richards) and poor outcast Suzie Toller (Campbell), and hires lawyer Kenneth Bowden (Murray) to defend him. At trial, Suzie admits that she and Kelly had made everything up to get revenge on Lombardo: Suzie for him failing to bail her out of jail on a minor drug charge and Kelly for him having an affair with her mother, Sandra. Kelly's mother is humiliated by the scandal, and Lombardo and Bowden negotiate an $8.5 million settlement for defamation. In reality, however, Lombardo and the two girls were accomplices who used the trial as a way to get money from Kelly's wealthy family. To celebrate their success, the three of them have sex.
The film takes place in the 1940s, when Shanghai was under Japanese occupation. A young Chinese woman named Mrs Mai is sitting in a luxurious cafe. She makes a phone call, signaling a group of resistance agents to load their weapons.
In the stereotypical high school community of John Hughes High in Southern California, sexy Priscilla (Jaime Pressly), a popular cheerleader, separates from her football star boyfriend, Jake Wyler (Chris Evans). After Jake discovers that Priscilla is now dating peculiar Les (Riley Smith) just to spite him, one of Jake's friends, Austin (Eric Christian Olsen), suggests seeking retribution by turning Janey Briggs (Chyler Leigh), a "uniquely rebellious girl", into the prom queen.
Deuce Bigalow (Rob Schneider), an insecure fishtank cleaner (aquarist), is fired for cleaning the tank at a public aquarium in the nude. Deuce is unsuccessful in attracting women, so he attempts to keep himself busy at work. On a house call, he meets an Argentinean male prostitute Antoine Laconte (Oded Fehr). Antoine is going on a business trip, and so asks Deuce to care for his lionfish and protect his home while he is away. Deuce accidentally sets Antoine's kitchen on fire when trying to make a grilled cheese sandwich in the toaster, and breaks an expensive fish tank.
Joel Goodson is a normal high school student who lives with his wealthy parents in the North Shore area of suburban Chicago. His father wants him to attend Princeton University, his alma mater, so Joel participates in Future Enterprisers, an extracurricular activity in which students work in teams to create small businesses.
After moving from Michigan to Florida, Aileen Wuornos, a prostitute, meets Selby Wall in a gay bar. After initial hostility and declaring that she is not gay, Aileen talks to Selby over beers. Selby takes to Aileen almost immediately, as she likes that she is very protective of her. Selby invites her to spend the night with her. They return to the house where Selby is staying (temporarily exiled by her parents following the accusation from another girl that Selby tried to kiss her). They later agree to meet at a roller skating rink, and they kiss for the first time. Aileen and Selby fall in love, but they have nowhere to go, so Selby goes back to her Aunt's home.
Best friends and nerds Lewis Skolnick and Gilbert Lowe enroll in Adams College to study computer science. They are kicked out of the freshmen dorms by the Alpha Betas, a fraternity composed primarily of football team members, after the Alpha's carelessly burn down their frat house. Dean Ulich sets up the freshmen in temporary quarters in the school's gymnasium, but allows them to rush the fraternities to alleviate their housing situation. Lewis, Gilbert, and other nerds fail to gain fraternity membership, but are able to rent and completely renovate a rundown two-story campus house.
Shampoo is set during a 24-hour period in 1968, on the eve of a presidential election that would result in Richard Nixon's election to the American presidency. George Roundy is a successful Beverly Hills hairdresser, whose occupation and charisma have provided him the perfect platform from which to meet and have sex with beautiful women, including his current girlfriend Jill.
While playing a game seven minutes in heaven at a party in 1985, 12-year-old Charles "Chuck" Logan (Connor Price) refuses to kiss a goth girl named Anisha (Sasha Pieterse). In retaliation, Anisha places a curse on Chuck, so that every single woman he sleeps with will break up with him and marry the next man who asks her out.