Last week, I got a call from Scott Arpajian, who wanted to tell me about his new Web site. “It's called Dizzywood,” Arpajian said, explaining that the site was a virtual world for ages 8 to 12. “Would you like a tour?” “Sure,” I said, adding that coincidentally I already had an account. That was because months earlier, when Dizzywood was still in development, my 10-year-old daughter, Clementine, had come home from school with a code to activate a Dizzywood account. I thought nothing of it because we live in the sort of rarefied town near Silicon Valley where it seems as if half the population is developing Web sites while the other half is beta testing them. Children here swap beta invitations the way an earlier generation swapped baseball cards. Now, as I typed the password, I asked, “Can I just sign on as hippohead3000?” There was a brief silence on the other end of the conference call, where Arpajian and Sean Uberoi Kelly, another Dizzywood founder, waited for me to log in. Then Arpajian cleared his throat and asked, “Did you say hippohead3000?” Before I could answer, Clementine's avatar - a girl with long dark hair and a backpack - popped onscreen. They explained the site as I propelled hippohead3000 on a skateboard through a world of wizards, levitating fruit and flower patches. Then I logged off. Later that day, I received a curious e-mail message from Arpajian, which said, “I didn't want to mention this on the conference call, but my jaw hit the floor when you logged in with hippohead3000.” The reason, he explained, was that during the site's early days, when a few dozen anonymous beta testers were the only users, hippohead3000 was such a diligent, ever-present tester that she captured the attention of the adults monitoring the site. “We often invoke the account name,” Arpajian wrote, explaining that sometimes he wonders, when considering a new feature, if it is one that hippohead3000 would like. “Small world.” Small world, indeed. Now I was floored. My child spent so much time on Dizzywood that the staff knew her intimately enough to create features that would appeal to her. Thrilling, and yet creepy. All those afternoons when I thought I had kept an eye on her while she sat in the kitchen with a laptop? She had been living a double life right in front of me. Maybe I felt so weird about the Dizzywood situation because, all of a sudden, I realized there were people online who knew an AlternaClementine. “Get used to it,” said Amy Bruckman, an associate professor of technology at Georgia Tech who studies how children interact with computers. “Identity formation is a key part of what kids go through, and these sites offer that opportunity, as well as all the other things - like interacting with peers and working toward goals that kids like to do. We're going to see it more and more.” Already, when Clementine plays online Scrabble, she tells her opponents she is a French single mother of twins (Jacques and Pierre) and has recently moved stateside to improve her English. And at Zwinky.com, another of her haunts, she pretends to be a college student in a dorm. I only hope that getting away with little white lies today won't make her think, 20 years from now, that she can get away with an Augusten Burroughs-style memoir about her mother. Alas, this is just the beginning. The success of such destinations as Club Penguin and Webkinz has paved the way for an explosion of new sites for children. As of last month, more than 100 new virtual worlds had started up or were in development, according to Virtual Worlds Management, a trade group based in Austin, Texas. Many sites such as Empire of Sports, Planet Cazmo and Xivio are aimed at so-called tweens, ages 8 to 12. For those who have outgrown Club Penguin but who are too young for MySpace, the sites offer a hybrid of a games site and a social network. This year, more than 12 million children nationwide under the age of 18 will visit at least one of these sites, and that number will grow to 20 million by 2011, according to the research firm eMarketer (which didn't estimate how many children would pretend to be French single mothers). “As much as parents try to control kids, they find a way to live their own lives,” Bruckman said. “You should take a look at these sites yourself.” I wanted to. But every time I tried, I couldn't focus. One children's virtual world is much like the next to me. When it comes to customizing my avatar's hairstyle, one ponytail looks like all the others frozen in cyberspace like horse tails that don't bounce. I needed a guide. The next day, I found Clementine at the kitchen table, where she was watching television, doing her math homework and sending instant messages to three friends. Simultaneously. Just observing her generation's ability to multitask gave me a terrible headache. Yet, I persevered. “Can you give me a tour of some of these sites?” I asked. “Sure,” she said, without a break in typing. “Can you bring me the other laptop, so I can keep talking to my friends on this one?” I sighed. Then I read from my list: “First stop, Planet Cazmo.” “I haven't heard of it,” she said. “Well,” I said, consulting my list again, “at this one you can ...” But before I had finished the thought, Clementine had figured out how to take us to a planet called Funkitron. Then, as terrible pop music began blaring, she coolly scrolled through the selections of an onscreen jukebox (where did that come from? I still don't know) to change the tune. “Now what are you doing?” I asked, as she clicked on a little box. “I'm buying hair,” she said, adding with a frown that they don't have much choice. Next she clicked quickly and intuitively through all the features on the menu bar before concluding: “This site is made for kids, not teenagers. See how you see your person onscreen as a little kid?” In other words, it was w-a-a-a-y too uncool to be aspirational for 10-year-olds who read Seventeen magazine (but who won't read it in seven years). I nodded. Next, we went to Whirled.com. It didn't look that different from Planet Cazmo to my untrained eyes. “It's trying to be like a Facebook for kids,” Clementine explained patiently, pointing. “See, this is like your profile. And this is where you keep track of your friends.” Oh. In the next hour, she showed me around Habbo.com, a Finnish site where teens interact with celebrity avatars (“I never go to this one, because you need a different version of Adobe Shockwave, and installing it takes forever,” she said); Pixie Hollow, a Disney site where users play in a sprite's magical world (“Very bad, unless you are 4 years old and your main goal in life is to be a fairy”), and Zwinky (“I like it because you can choose whether to be a kid or a teenager”). Then we went to OurWorld.com, a site aimed at ages 11 to 15, that she had never seen. “It looks much more three-dimensional,” Clementine said, heading into the Buzz Coffee House where six users with names like Air Death milled. She pointed to a user named Xzibit and mused, “He's working as a barista behind the counter.” He was? “Let me have a shift,” she typed. In response, Xzibit asked her to be his friend. She accepted. Then she started making coffee. “I might hang out on this one for awhile,” she said. “But I wanted you to show me Dizzywood,” I said. “I heard you hang out there a lot.” “Not anymore,” she said. “That site got way too crowded. You can't walk around without knocking into people.” “You're very fickle,” I said. “What does that mean?” she asked. I smiled. At last, I knew something a fifth-grader didn't. - NYT __