It's common knowledge: The day after a date with a guy she likes, a girl will dissect every sentence, every word, and every gesture to try to determine if said guy will call her in an acceptable amount of time to go out again. If he doesn't call within that time frame, then the girl talk begins.

"Why didn't he call me?"

"Well, maybe he lost your number. Or maybe he got into a car accident and is in a coma. Or maybe he got food poisoning from the salmon he had at dinner and has been puking for the last few days and is afraid to call you when he's throwing up since that's gross."

"He's a vegetarian."

"Well, maybe there was salmonella in the spinach?"

And then there are the old standbys that we girls offer each other further along in the dating/relationship process. Namely: "You're too good for him," or "What an idiot! He doesn't realize how lucky he was to be with as someone as amazing as you!"

When it comes to the world of dating, relationships, and love, it is the job of the best girlfriend to offer advice, compassion, and insults (toward the guy, of course). In girl world, there does not exist the simple "Maybe he's just not that interested?"

WHOA! That phrase would erase the entire girlfriend manifesto, but that's the simple message offered by the movie "He's Just Not That Into You."

Based on a book of the same name by Liz Tuccillo and Greg Behrendt, the movie follows the relationship ups and downs of nine 20-30 year-olds trying to figure it all out in Baltimore. The nine characters' stories are interwoven as they try to help each other navigate the trials of dating, marriage, and just meeting people.

The movie focuses on the character of Gigi—a zealous 20-something played by a slightly neurotic (in a good way) Ginnifer Goodwin. Gigi wants to find true love, and she's not afraid of putting herself out there to get it. She's the kind of girl that convinces herself that she's in a good relationship when the guy breaks up with her every weekend so that he's "unattached." She just really wants to have a boyfriend.

First there's Conor (Kevin Connolly), a real estate agent that Gigi meets through her friend Janine. Conor would be perfect, except he's hung up on Anna (Scarlett Johansson) who is his best friend (and someone with whom he has intimate conversations), but won't sleep with him. Anna is falling for newlywed Ben (Bradley Cooper), who married his college girlfriend Janine (Jennifer Connolly) because she gave him an ultimatum—either they get married or they split. Yeah, it's complicated.

Because Connor is so focused on getting Anna into bed and into a long-term relationship, he totally forgets about Gigi the minute they walk in opposite directions. Gigi doesn't forget about him though, and spends days checking her cell phone obsessively and sitting by her home phone to make sure she doesn't miss the inevitable (right? I mean, they had a good time) call. Finally she calls him on her own—only to utterly botch the message she leaves.

In a last ditch attempt, Gigi drops by a dinner place she knows that Conor hangs out at, hoping to run into him and hopefully reinitiating the spark she thought they had that first time. Instead, she meets Alex (Justin Long) who is Conor's best friend. Alex explains a simple concept to Gigi that her girlfriends neglected to explain: If he hasn't called, he's just not that into you!

And so, they're all off to the races. Gigi tries dating many different men, always asking Alex for advice and getting his blunt returns. Conor tries to figure out where he and Anna are going, if anywhere, and Anna tries to seduce Ben away from his wife, and succeeds. Meanwhile, Janine tries to figure what happened to her marriage and why it's not as perfect as her newly renovated house.

And then there's Beth (Jennifer Aniston) and Neil (Ben Affleck). Beth and Neil are in a committed relationship—more committed than Janine's and Ben's—and have rings on their fingers that have been there for seven years. Neil doesn't believe in marriage, which for many women can be a blatant warning signal, but is nonetheless completely in love with Beth and doesn't realize why they need a piece of paper to prove that. Beth, however, has second thoughts about the whole situation when her younger sister gets engaged.

Then there's Mary (Drew Barrymore) who is a sort of ditzy advertising rep for a gay men's magazine who can't quite figure out how all this new technology works when dating. There's e-mail, cell phones, home phones, work phones, and Myspace (clearly this movie script was written a few years ago). And then, does videochatting with someone while drinking coffee count as a date?

Overall, the movie is smart and witty, and Ginnifer Goodwin and Justin Long carry it well with their back-and-forth banter. Scarlett Johansson's character rings false in a lot of scenes, as if she's not convinced about the part she is playing. I wish that Drew Barrymore had been featured more; her perplexity was hysterical, and seeing more of her confusion would have helped the film in the humor department. Jennifer Aniston seems to have the same facial expression the entire time, but you can't help feeling sorry for her when she sits next to a single Wiccan (male witch, as he so helpfully explains) at her little sister's wedding.

"He's Just Not That Into You" is honest. There are happy endings and sad endings, and that's usually how life turns out. There are rules and there are exceptions. The goal is to find the person who's your exception.