Texting is short, fast, off-the-cuff, and it feels like spontaneous conversation. It's also a sign of belonging.

More than three-quarters of all U.S. teenagers have cell phones, and of those, a growing number have smart phones—cell phones that are always online.

A report published March 19 by the Pew Center’s Internet and American Life Project tells us how much, and exactly how, teens use them. We already know teens text a lot: A now-famous October 2010 survey by the Nielsen Co. showed the average teenager sent 3,339 texts a month.

Teens text way more than they call. The Pew report shows it’s getting to be even more like that. The Pew team called 799 people ages 12-17 and a parent or guardian. About 77 percent had cell phones, and about 23 percent had smart phones. Seventy-five percent of teens text, and they’re texting more. Calls and texts are up, with the frequency of texts increasing and calls decreasing.

Teens 14-17 went from a median of 60 texts a day in 2009 to 100 a day (pretty near the Nielsen number) in 2011. Girls are the biggest texters, averaging 100 a day, but all groups, ethnicities, and income levels are texting more.

Heavy texters also tend to be big talkers, making more calls, too.

Sixty-three percent affirmed that they exchange texts daily with those who are important to them. Only 39 percent said they call them every day. Land lines? They’re for people born in years that start with 19. Only 14 percent said they used land lines daily. Only 6 percent eMailed daily.

So what is it about texting? This is a media world young people have made in their own image. It dominates their social communications, leaving behind even social-media sites (29 percent). Texting language, long familiar, is supercharged, creative, and everywhere, full of slang, acronyms (the honored OMG for Oh, my God!) abbreviations (u for you), de-voweled words (kybrd for keyboard), pictograms (the clever sideways heart in i <3 u for I love you), and a snowstorm of emoticons and !!!!!!

“All along, this has reflected the desire of teens to create their own group language and use it to stay in contact,” says Amanda Lenhart, senior research specialist at Pew and the study’s leading researcher. She cites a “network effect”: “Once you reach a critical mass in your network of friends, you begin to text them all the time, and they expect you’ll do that, and you expect them to do it.” We become nodes in a network and express that network through connectivity.