If that smartphone in your pocket or purse seems critical to your daily life, imagine how important it could be to your spouse's divorce lawyer.

Though small and sleek, the modern cellphone brims with information divorce lawyers and judges are eager to see, such as text messages, photographs, videos, e-mail, Internet browser links, call histories, calendar entries and GPS tracking data.

Add that to the golden triumvirate through which private misbehavior now becomes permanently public -- Facebook, Twitter and YouTube postings -- and lawyers practicing family law have more electronic means than ever to settle those timeless "he said, she said" arguments with devastating certainty.

Consider the possibilities:

• Not bad-mouthing me to the kids? Really? Take a look at this text message you sent them.

• Can't find a job? Then why do you spend all day noodling websites that have nothing to do with work?

• In Omaha on business? So how did your iPhone "check in" on Facebook at this fancy restaurant in Boston? And who's with you in that picture?

In a recent survey of more than 800 divorce lawyers by the American Academy of Matrimonial Lawyers, 92 percent said they've seen more cases during the last three years using evidence taken from iPhones, Droids and other smartphones.

Earlier surveys showed similar increases in family law cases that included social media and e-mail evidence, said Ken Altshuler, president of the academy.

The survey found that text messages are the most common form of evidence taken from the phones, followed by e-mails, phone numbers, call histories and GPS and Internet search results.

But ferreting out the details of an illicit relationship isn't really the purpose of collecting electronic evidence, lawyers said. Rather, it's all about the custody of two things that often are at the heart of family disputes: children and money.

Anita Rodarte, a lawyer with a matrimonial practice in Kansas City, Mo., once represented a man who was fighting a demand from his ex-wife for additional maintenance payments. Her Facebook postings, however, revealed that she had been spending lavishly on a maintenance issue of her own: cosmetic surgery.

"What about a spouse who is seeking support because they can't find a job, and you look at the cellphone bill and they're spending all day long chatting on the phone?" Rodarte asked.

Altshuler, who practices family law in Maine, said electronic evidence is particularly good at giving clues whether one party in a divorce case is selling assets or trying to hide assets. He once found a cryptic text message -- "I'm sending you $1,000. You know what to do with it." -- leading to evidence that his client's former spouse was hiding assets.

Lawyers said that on custody issues, judges are particularly sensitive to what parents say about each other to their children. Texts often illuminate that subject.

"Who is going to foster a good relationship?" asked Rodarte. "Is that going to be the parent who is making the disparaging remarks?"

And credibility always is a key for judges. One of Altshuler's clients found a photo on her husband's cellphone of him drying a load of marijuana. She forwarded it to her own phone while he was in another room.

When the husband denied having issues with drugs, the court was treated to 30 seconds of stunned silence as he looked at the picture, Altshuler said.

"All you need is for the judge to like your client and dislike the other person," Altshuler said. "The rest is easy."

But sometimes electronic evidence makes resolving a custody or paternity issue almost too easy. Kansas City lawyer Hugh O'Donnell once uncovered a YouTube video that a man, who was claiming paternity of a child, had posted a couple of years before.

During an appearance on a television reality show, the man had adamantly claimed the child wasn't his.

That video, and not the man's testimony, decided the issue, O'Donnell said.

"Lawyers know that if this [kind of evidence] gets in front of the judge there will be repercussions for the client," O'Donnell said.

Parties in a lawsuit generally are entitled to electronic evidence, and laying hands on it has become fairly routine, lawyers said. Estranged spouses generally can count on text messages they've sent to each other to emerge if they're material to the case.

Children and spouses' friends also are steady sources of electronic communications. And information from shared computers and telephone accounts also are fair game, lawyers said.

Lawyers can request that people not destroy electronic evidence before the lawyers look at it.

The impulsive nature of electronic communications -- often visceral and sharp -- can make it powerful evidence in a divorce case already infused with raw emotions, lawyers said. In the light of calm reflection, even an idle threat looks far worse on a page with an evidence sticker attached.

"It's there, it's in print and it's hard to run away from," Rodarte said.

So how to avoid that moment? Lawyers advise never to write or text anything that you wouldn't want a judge to read.

"Criminal lawyers see the worst people acting their best," Altshuler said. "Divorce lawyers see the best people acting their worst. Even the most sane people act crazy under extreme emotional pressure."