NOTE: This spoiler was sent in by Jonathan F who says..."There is a lot of cutting back and forth between the four main characters in an Altman-esque way, but the end result is very satisfying."
The movie begins with Olivia (Jennifer Aniston) cleaning the home of a client. As she's cleaning a bedroom, she finds a vibrator in the night stand. She keeps opening and closing the night stand, deciding whether to take the vibrator out or not. Eventually, she does and turns it on. Intercut with this scene are scenes involving Olivia's married friends. Christine (Catherine Keener) and David (Jason Isaacs) are meeting with an architect, who's showing them a model of the proposed add-on to their home. It will be very high and allow them to view the ocean from their balcony. Christine says she loves it, and they agree to proceed. Franny (Joan Cusack) and Matt (Greg Germann) are the richest and happiest of Olivia's friends. They are debating whether it's appropriate for a child to have $90 shoes. Franny thinks since the child is going to outgrow them anyway, they should spend $20. But Matt argues that since the kid's feet are growing, they should spend the extra money for better support. Lastly, we meet Jane (Frances McDormand) and Aaron (Simon McBurney). Aaron can't decide what shirt to wear for the evening, and Jane is losing patience with him.
Next, all four friends are at dinner with their husbands (except for Olivia, who's single), celebrating Jane's birthday. Jane makes a toast about how she couldn't go through life without her friends. Franny and Matt announce that they've bought a table at an ALS charity dinner and invite everyone to sit at their table. They are very wealthy, and Christine asks them who they've decided to donate their money to. Franny says they're just going to give it to their child's school. Jane asks how much money is involved, and Franny reveals that it's $2 million. Jane says they should give the money to Olivia because she's cleaning houses, which embarrasses Olivia. Aaron says there's a big sale on cashmere the next day and asks if anyone would like to join him.
Driving home, Christine thinks that Aaron is so gay. Meanwhile in their own car, Jane tells Aaron that Christine and David haven't had sex in a year, and Christine's never even seen David's anus.
At the clothes sale, Aaron is trying on sweaters, and a man begins flirting with him. He asks Aaron to dinner, but Aaron shows him his wedding ring, saying he's married. The man says Lucky man, and Aaron is about to correct the man, but he walks away.
Olivia goes to the home of a prospective client Marty (Bob Stephenson). He is overweight and slovenly, and his house is a total mess. He asks Olivia how much she charges, and she says $65. He says he was hoping it would be $50, and after a little hesitation, she says that's fine.
Olivia goes to the farmer's market with Jane, who's angry at a driver who tailgates her. While at the market, Jane sees a friend with a new baby and makes a joke about the boy's name. She also thinks Olivia was wrong to accept only $50 for cleaning the new client's home.
Franny is working out with her trainer Mike (Scott Caan) and thinks he should go out with Olivia. Mike and Olivia go on a blind date to a diner, but Mike keeps looking at a girl across the way and says she's a girl from junior high who broke his heart. Eventually, he goes to sit with the girl while Olivia fumes. Olivia goes to pay the bill and Mike stops her, apologizing. He says he wants to go out with her again. She tells him she's a maid.
Meanwhile, Christine and David are working on a screenplay. They don't agree on the character's lines. There is a lot of noise going on because of their house renovation. Christine's eating cookies, and David says she should stop eating so much because her hips are getting bigger. She is hurt by this comment and asks why he would say such a thing. He replies that she would want to know the truth. So she tells him that he has bad breath all the time, and if that hurts him. He says no.
Olivia meets Christine at a department store, where Olivia gets a free sample of a face lotion. She goes all over town getting free samples. She begins taking Mike to clean her clients' homes. He doesn't do much while she cleans, but when they're finished, he asks for a cut since he helped. She reluctantly gives him money.
Aaron is in a deli getting some food when another man strikes up a conversation with him. He is wearing a wedding ring, so Aaron decides it's okay to talk to him. They are very flirtatious with each other. Later, Aaron tells Jane about his new friend and says they're going to the movies together.
On another cleaning trip with Mike, Olivia asks him how much he makes as a personal trainer. She likes the pay, so she tells Franny that she needs $1800 to get certified as a trainer. Franny replies that Olivia is her only friend who doesn't like to exercise. Olivia is hurt that Franny won't give her the money.
Christine's neighbors are giving her the cold shoulder because of her home construction, so she confronts one of her neighbors. When she does, she sees what a monstrosity her house is, blocking everybody's view. She runs out and tells all the workmen to stop. David is furious with her and says she knew what she was getting into. Later while cooking dinner they continue to argue, and Christine burns her hand on the hot pot. David doesn't ask if she's okay. Christine asks David why he never asks if she's okay. He says it's her responsibility to tell him she's not hurt. She realizes he doesn't love her.
Aaron is at the movies with his new male friend, also named Aaron. Aaron #2 is looking at Aaron #1 rather suggestively. After the movie, they decide to go back to Aaron #2's place for a bite to eat. There, they talk about their wives.
At the same time, Jane is at Old Navy and is upset when two people cut in line in front of her. She causes a ruckus and is asked to leave. Instead, she runs into the glass window and breaks her nose.
At the hospital, the friends meet to see how Jane is doing. Jane's going to be fine. Aaron arrives and says his phone has been off. Franny apologizes to Olivia about their argument about the money for the personal training certification.
The next day, the women go with Jane to her studio to get outfits for the ALS charity dinner. Jane gives them all the outfits, which she designed.
Jane and Aaron then have lunch with Aaron #2 and his wife. Jane complains about the service and almost causes another scene. After lunch, Aaron #2's wife says Aaron is so gay. In Jane and Aaron's car, Aaron asks Jane why she's so angry. She reveals that there's no longer anything to look forward to in life.
Olivia is cleaning another home with Mike (the house from the opening scene with the vibrator). Mike gives her a present, which is a maid's uniform. She puts it on and they have sex. When they're through, he says he has to go. But before going, he asks for his cut. She gives him the money, but follows him to a restaurant, where he is meeting the girl from the diner.
Olivia decides to stop cleaning houses and calls her clients to tell them. When she calls Marty, the slovenly guy, he asks her out. She says okay.
Christine decides to divorce David. She finds comfort with Jane and Aaron, who tell her it will be all right. Later we see Christine at her desk looking sadly at the desk David used to sit at. Their house is up for sale.
On the night of the ALS benefit, Olivia picks up Marty. She realizes he is a nice guy, and they have a lot in common. When they get to the dinner, Matt keeps asking him what he does for a living. Marty hems and haws about various investments, but he looks embarrassed.
As they drive home, Matt tells Franny she was the most beautiful woman there. In their own car, Aaron tells Jane she was the most beautiful woman there. And in Marty's car, he tells Olivia that he doesn't work because he's actually rich. She looks surprised and kind of happy.
Cut to Olivia and Marty in bed. She asks him why he bargained her down to $50 when they first met. He says he has issues. She says that's okay, she has issues too.