Wondering where your kid has been lately? Check with his virtual persona — his avatar. Most likely you'll find him at one of these four popular playgrounds.

By Damon Brown

For Tweens

Virtual world: clubpenguin.com

Kids create penguin avatars, decorate igloos, and play games with millions of other visitors. They can start a blog, perform in online plays, or contribute member news to the weekly newspaper, the Club Penguin Times.

Emotional draw: Kids get to test their parental skills by nurturing, protecting, and caring for their penguins. Feed a penguin too much and it gets a bellyache; feed it too little and it cries.

Cool factor: The Web site rewards creativity, inviting kids to submit anonymous fan art, which is featured in the Club Penguin Times or in the community section. Guidebooks to the virtual world make it easy for even young kids to design a penguin paradise.

Real-life rules: Run by Disney, Club Penguin is free to visit. Additional membership privileges, like the option to decorate igloos, are available for $5.95 a month. Instant-messaging chats come in two forms: Standard Safe Chat, which allows players to type messages that are filtered by a team of live moderators, and Ultimate Safe Chat, which limits conversations to a drop-down menu of preapproved words and phrases. An extensive shop sells T-shirts, toys, and baseball caps.

For Teens

Virtual world: habbo.com

Style is hot at Habbo, where avatars traverse the three-dimensional cartoon city decked out in hip sunglasses, feather boas, or varsity jackets.

Emotional draw: Kids who crave independence dive into Habbo to rehearse their imminent transition into adulthood. They choose new hairstyles, create social bonds with other teens, and find, furnish, and live in their own virtual apartments. It's like training wheels for the real world.

Cool factor: In Habbo's online forums teens talk about what's on their minds, from trouble at school to a new crush. (The Habbo staff monitors the boards to curb inappropriate behavior.) A "tag" system lets users know where on the site to find popular discussion topics. There are also mini games — goofy diversions like snowball fights and log-rolling contests — that encourage group interaction among Habbo's several million members.

Real-life rules: Kids get their own e-mail accounts, and adult-controlled characters called guides serve as monitors in case visitors need help. While there's no monthly fee, buying clothes and participating in advanced virtual events — like moving to a more sophisticated apartment — require Habbo coins, which cost about 20 cents each.

For Boys and Girls

Virtual world: gaiaonline.com

Combining the visuals of Japanese anime cartoons with cheeky humor, this world takes players ages 13 and up on an adventurous treasure hunt. Avatars wear distinct clothing and hairstyles and can get "in" with cool cliques called guilds. Like anime, Gaia Online attracts boys, but girls can be found in the world too.

Emotional draw: Only serious fans of anime seek out this exotic, insular community. Not everyone can appreciate the adventure hunting or the visual style, but for kids who find it appealing, playing on Gaia is like being admitted to the most exclusive club in town.

Cool factor: Kids can get creative with Gaia's fantasy art, poetry, and storytelling, or take a break by playing pinball, going fishing, and doing puzzles. And since the games usually involve solo play, kids don't have to depend on others for fun. They can also take a game (like the pinball experience), plop it into another virtual world and play.

Real-life rules: There is no membership fee, but accessories like mobile phone pictures, avatar upgrades and Gaia Online-branded clothing cost real-life money. Gaia Cash, the in-world currency, can be purchased several ways; Target, for example, sells gifts cards.

For Girls

Virtual world: barbiegirls.com

Painted in vibrant colors, this community invites gals to design their avatars' clothes, style their hair, and explore chic neighborhood haunts.

Emotional draw: It's all about sophistication in this girly world. Barbies hang out with friends, decorate their apartments, and do other grown-up activities. Girls dealing with peers and school can benefit from the positive daily fortunes that encourage them to take their dreams to the next level by creating a story or picture.

Cool factor: B Bucks are earned by acting in movies, playing simple games, and completing character-development activities. With B Bucks girls can shop for clothes, furniture, or even a virtual pet. There's also a small arcade with diversions like air hockey. Finally, music and videos can be downloaded to the specially branded Barbie MP3 player (sold separately).

Real-life rules: The site's instant-messaging service, B Chat, enables tweens to talk with the other 11 million Barbie Girls, but parents control the amount of freedom allowed in conversations. The Parents' Place section also lets you decide how much time your daughter can spend in the virtual world. Monthly membership is $6.

Whose Avatar Is That?

While there may be limitations to the icons kids can create to represent themselves — for example, avatars in Club Penguin must be penguins — kids can often pick the gender, clothing, hairstyle, or body type. "Someone who invents a sexy, sultry alternate identity may not realize the impression she is giving to the outside world," says Barbara Melton, a licensed professional counselor in Charleston, South Carolina, and coauthor of What in the World Are Your Kids Doing Online? (Broadway Books). And since tweens and teens use avatars to portray how they want to look or be seen by others, parents should take note. If your child devises a completely different identity, ask her why she designed her avatar that way, then suggest she create a second with characteristics more like her own. Kids should divide their time between the "fantasy" avatar and the more realistic version.

Living in a Virtual World

Online communities aren't just a time-suck for kids — they also have their benefits, according to experts. Kids can learn life skills, such as managing money, setting up a home, and planning for the long term, says Melton. "Online worlds also encourage kids to work together to accomplish goals and overcome challenges," she says. "And since kids can choose to be anonymous, it's a safe place for them to practice social dexterity without worrying about being judged by their friends in the real world." That might be why online environments are especially popular with shy tweens and teens who are less comfortable interacting with their peers. But whether or not your daughter is a social butterfly, pay attention to how much time she spends on the computer. Research her favorite virtual world to see what others say about it — check commonsensemedia.org — and even sign up yourself. "Ask her to help you create an avatar," suggests Melton. "That way you'll show interest in what she's doing and learn about her fantasyland at the same time."

Originally published in the June 2009 issue of Family Circle magazine.