They can go bowling with SpongeBob Squarepants at Nick.kids.us, plunk a piano keyboard at Music.kids.us, and learn about mummies at Mummies.kids.us. There are fun facts about the solar system at Space.kids.us and motorcycles at Knex.kids.us.
Beyond that there are only 16 more Web sites in the .kids.us Internet domain, a letdown to those who had hoped that it would host enough material so that kids wouldn't have to navigate the unprotected wilds of the Internet at large.
"It's disappointing; I wish it was fully deployed," said Illinois Republican Rep. John Shimkus, who sponsored the bill thatin 2002.
But while Congress and administrator NeuStar set plenty of restrictions to keep online predators and inappropriate content out of the .kids.us domain, they didn't provide many incentives to bring Web sites in, Internet experts say.
"You're dealing with a commercial venture in some instances, and with nonprofits that might not have the extra money," said Donna Rice Hughes, president of the online child safety group Enough is Enough.
Congress turned to the idea of a special Internet domain for children under 13 after several attempts to ban or segregate online pornography failed in court in the late 1990s.
Lawmakers decided it would be easier to set up a .kids domain within the United States' own .us domain rather than work through the international nonprofit body thatlike .com and .org.
In theory, parents could adjust their childrens' Web browser so they could only view Web sites within the .kids.us domain, making it easy to avoid objectionable content.
Web sites with a .kids.us address can't contain pornography, violence, or references to drugs and alcohol. Message boards, chat services and other interactive features are also prohibited from setting up shop unless the operators can promise that kids won't be exposed to inappropriate material.
All material must pass a content review before it is posted, and .kids.us sites can't link to sites outside the domain.
The online real estate doesn't come cheap. Users must pay an annual fee of roughly $150 to register the name, and the content review costs an additional $250 per year. Those looking for a .com name, by contrast, can pay as little as $7 per year.
These restrictions are compounded by a 1998 privacy law that prevents Web sites from collecting personal information about children without their parents' consent.
"Why would any kids' site pay $300 to register in a place that has nothing really driving anyone to it and special liability for the sites themselves?" said Parry Aftab, a New York lawyer and activist who works on online child-safety issues.
More than 1,700 .kids.us names were reserved after the domain was opened for registration in June 2003, but two years later only 21 Web sites are up and running.
"I don't think we're disappointed; certainly the kids.us space is serving a valuable need," said Keith Drazek, NeuStar's manager for industrial and government relations.
Drazek said the registration fee is set by retail domain-name sellers, and he declined to say what NeuStar charges as a wholesale price. The content-review process takes time and effort as well, he said.
Only six Web sites or so have been rejected because of inappropriate content, said Bob Dahstrom, chief executive of Kidsnet, the company that handles the content review.
"We'd be happy to review more," he said.
John Marshall University law professor David Sorkin, whose Law.kids.us site was rejected because it contained a Supreme Court opinion that contained profanity, said the lack of content in the domain has stymied its growth.
"It's sort of a chicken-and-egg problem, I suppose," he said.
Lackluster promotion hasn't helped either, Aftab and Rice Hughes said. NeuStar should lower its prices and give away domain names to nonprofit groups to encourage more content, they said.
NeuStar has produced an informational brochure and participated in a public forum last July, Drazek said, and the company can't give away domain names on its own.
Shimkus said he's still trying to raise awareness about the domain but he can understand why the response has been tepid.
"I never want to make enemies of people who may see the light, and I don't think (the restrictions) are onerous. But what I do think it does is that if they have a similar dot-com site where they can market goods, they'd rather be there," he said.