Teens are not dreaming of portability (like so many adults i meet). They are happy to make new accounts on new sites; they enjoy building out profiles. (Part of this could be that they have a lot more time on their hands.) The idea of taking MySpace material to Facebook when they transition is completely foreign. They're going to a new site, they want to start over.

While this feeling of ephemerality is not universal amongst teens, it's far more prevalent than you'd ever see in adult culture and it has some significant implications for design:

Focusing on "lock-in" will fail with these teens - they don't care if they lose track of something they put hours into building.

Teens are not looking for universal anything; that's far too much of a burden if losing track of things is the norm.

Paying for an account can help truly engaged teens remember their accounts (i haven't found any teen who permanently lost their MMO login) but it can also be a strong deterrent for those accustomed to starting over.

The numbers that people cite concerning accounts created are astoundingly inaccurate and are worthless for talking about usage or unique participants. (added tx to a comment by Rich)

I should note that i don't think that the answer is "help teens remember passwords." I actually think that this tendency to shed is advantageous in the way that we shed clothes every year because the "old me" is no longer relevant. Technology is a bit too obsessed with remembering; there's a lot of value in forgetting.

"I think it's definitely going down -- a lot of my friends have deleted their MySpaces and are more into Facebook now," said Birnbaum, a junior who spends more time on her Facebook profile, where she messages and shares photos with other students in her network.

From the other side of the classroom, E.J. Kim chimes in that in the past three months, she's gone from slaving over her MySpace profile up to four hours a day -- decorating it, posting notes and pictures to her friends' pages -- to deleting the whole thing.

"I've grown out of it," Kim said. "I thought it was kind of pointless."

Such is the social life of teens on the Internet: Powerful but fickle. Within several months' time, a site can garner tens of millions of users who, just as quickly, might flock to the next place, making it hard for corporate America to make lasting investments in whatever's hot now.

Take Xanga, the hot social networking site before MySpace: In October 2002, the typical Xanga user spent an average of 1 hour and 39 minutes a month on the site, a figure that declined steadily, reaching only 11 minutes last month, according to Nielsen-NetRatings. Friendster, another older site, hit its first usage peak of 1 hour and 51 minutes in October 2003, and then hit another peak of 3 hours and 3 minutes in February 2006. But last month, the average user was on Friendster for a mere 7 minutes.

"They're not loyal," Ben Bajarin, a market analyst for Creative Strategies Inc., said of the youth demographic. Young audiences search for innovative and new features. They're constantly looking for new ways to communicate and share content they find or create, and because of that group mentality, friends shift from service to service in blocs.

Consider the most popular teen sites tracked by Nielsen-NetRatings. Topping the list last month were Snapvine.com, PLyrics.com, Picgames.com -- none of which appeared among the top 10 for April, or the list a year ago.

On any given day, Nick opines about anything from his favorite Detroit sports franchises to NASCAR to which players have the best and worst hair in the World Cup. On average, he makes two posts a day, combining his love of writing and sports to create what has already earned the designation of AOL's Sports Blog of the Week.

"I'm most impressed with how prolific he is," said Jamie Mottram, who appears on ESPN2's "Cold Pizza" as the program's blogging expert.

"Nick posts something just about every day and offers a nice mix of commentary, links, photos and quotes."

When I get home.....I will be doing my homework, because school comes before everything. Then with other stuff, I have hockey and friends.

So don't expect me to make as many entries and I usually do.

Peter Chernin, president and chief operating officer of News Corp, told the Financial Times that, although he and Mr Murdoch were very optimistic about its prospects when they acquired it last year, MySpace had exceeded their expectations.

"MySpace is more potent and powerful than even we knew," Mr Chernin says. "And it is becoming a more integrated part of people's lives." However, as efforts grow to attract more advertisers to the site, News Corp is facing two challenges. Young users have to keep wanting to use the site, rather than switch to a "cooler" alternative.

Also, advertisers have to feel confident their reputation will not be tainted by "inappropriate" content. Teachers and parents are concerned that, because information on MySpace is publicly available, it might put teenagers in contact with predatory adults. In terms of retaining its appeal, Mr Chernin said users had to keep feeling the site was theirs. "We don't want to change the fundamental look and feel of the site," he said. "We do not want users to have any sense that it is corporatised."

It took students one day to hack their way back to blogging Web sites after technicians blocked them on school computers.

But Fort Wayne Community Schools will keep trying to keep students away from the popular sites, spokeswoman Debbie Morgan told The Journal Gazette for a Sunday story.

School officials say blogging not only distracts students but makes them vulnerable to online predators.

"We don't put all these thousands of dollars of equipment out there in the schools for personal use," said Doug Coutts, the district's chief operations officer. "They're out there for educational purposes."

Students had been able to log on to popular sites including Facebook and MySpace during school, though they were not supposed to do so. Technicians started blocking the sites Thursday, but students had found ways around the new blocks by Friday.

Employers, bankers, insurance brokers, and college admissions officers are becoming wise by using social networking and blogging sites as an addition to traditional background checks, such as credit and criminal history.

The more than 70 million people using these sites make it easy for anyone who wants to learn about them.

"Unfortunately, I think most of the people who are posting those are only thinking about their intended readers," said Steven Rothberg, president and founder of CollegeRecruiter.com, the highest traffic career site used by students, recent graduates, and employers.

"If you're a 20-year-old college student and you like to get drunk on the weekends, you're probably going to put that on your profile because you want to hook up with other people that do the same."

Pennsylvania State University police used Facebook to identify 50 students who stormed the field after the football game against Ohio State this past season.

Naively, the students formed a Facebook group that university police said was titled something like "I stormed the field after Ohio State game."

Police officers were searching for another student who was accused of online harassment when they stumbled upon the group, complete with university e-mails and pictures that clearly incriminated the students.

Punishments for the students ranged from warnings to suspensions.

My daughter discovered online journals, or "blogs," when she was 16. After a lot of negotiating, she was allowed to start her blog on www.xanga.com. Her "xanga" had to be accessible by me. She couldn't post her real name, photos of herself, or her location, and I encouraged her to warn her friends not to either. But in keeping an eye on her xanga, I also had access to her friends' xangas. Surprise - this opened me up to a whole new world of insight into today's teenager. These kids can write.

To keep a blog going, you have to have the discipline to write daily. This puts today's young bloggers on the fast track to future Pulitzers. To keep your friends coming back, you have to be interesting, funny, intelligent, relevant. These kids are all that and more. Once I got past the immature spelling and punctuation (along with usual teen slang and vulgarity), I was treated to some of the best poetry I've ever read. All of their blogs together are a veritable anthropological study of high school life. One senior I know has, in four years, transformed from what seemed like functional illiteracy - incomplete sentences, poor spelling - into a blossoming philosopher headed for a major university.

Teens now use a broader array of online content and services. E-mail is still the number one activity at 89 percent, though it slipped marginally from the 92 percent reported in 2000. Visits to entertainment Web sites (TV, music, sport and movies) were noted by 84 percent of teens (up from 83 percent in 2000). The likelihood of teens going online to play games jumped to 81 percent, up from only 66 percent in 2000. Checking online news (76 percent), purchasing online (43 percent) and getting health information (31 percent) were also up.

In comparison with adults, teen play more online games, IM more, and have a higher propensity to go online to get news on current events.