Life and Romance in 160 Characters or Less

"You can send a quick little message saying you're thinking of her," the operations research analyst said. Then "you start paying attention not only to what the message says, but you care about the response time." There's a meta-message: The shorter the response time, the more she cares.

Text messages also feel more personal because the cell phone is always physically close, Lung said -- a feature that works for and against him. He recently got into an argument with a friend, for example, who sent angry messages in all capital letters, berating him for ignoring her. "She started insulting me over text message . . . and it was not a good scene. It annoyed the hell out of me," he said. "Text messaging will catch you no matter where you are."

Messaging alters language and composition style, said Tom Keeney, director of messaging for T-Mobile USA. Slang has gotten more detailed and sophisticated, making it possible to say more on a tiny canvas, much like poetry, he said. "It's almost like letters gave way to postcards. It was a way to say something on the go."

Text messaging became popular in the United States about three years ago, coinciding with the first television season of "American Idol," which allowed viewers to vote for contestants by sending messages to the show. Now, almost a third of the country's 200 million cellular phone subscribers use text messaging regularly for social or business purposes.

In a recent survey, more than 60 percent of U.S. adults used text messages to tell others they missed or loved them, according to a survey by Tegic Communications, a company that makes predictive-spelling software used on most U.S. cell phones. In the same survey, 27 percent said they used them to flirt, 7 percent to ask someone for a date, and 2 percent to break up. Two percent percent proposed marriage via text.

In Europe and Asia, where text-messaging started earlier, emotional messaging is more common, according to Tegic. Among Germans, 70 percent said "I love you" or "I miss you" over text; 13 percent of Italians and 12 percent of Chinese subscribers admitted to breaking up over text.

Alexandria resident John Mallory said he has developed emotional attachments to some old text messages but occasionally must erase them to make room for new ones. "It says, 'Your mailbox is 90 percent full,' " said Mallory, 24, opening his phone to read an old message. "I'm in a constant battle to pick which ones to save."

But the saved messages can come back to bite. "I've had a friend in particular whose girlfriend was going through his phone and saw flirtatious text messages to an ex-girlfriend," he said. And that was a deal breaker.