There are usually games, social activities, and a point/currency system.
Webkinz is one of the best known virtual worlds for kids.
Owned by the makers of the Ganz stuffed animals, players can feed and dress their pets, as well as decorate their virtual world.
Games vary from simple arcade activities to more educational trivia quizzes.
Webkinz can take on jobs, go to school, or just hang out with friends.
A purchase is required to access the website (one Webkinz animal provides a one-year subscription to the site). More » Disney-owned Club Penguin is a virtual world where users go around as penguins.
They can play games, chat, and decorate their igloos.
Anyone can use Club Penguin for free, but many of the features are available only to paying members. More » National Geographic's Animal Jam is a virtual world with a subscription option.
It allows kids to pick and customize an animal avatar.
The song, "All That I Want," is featured in a series of 2007 J. It was also used in a Webkinz Christmas commercial.
It was also featured in a season 1 episode of the hit TV series Gossip Girl.
The song, "Somebody Loved," is featured in the 2004 Todd Solondz film, Palindromes.