Porn is just one of many issues parents should be concerned about when their kids go online. Problems could be as dangerous as encountering a predator in a chat room, as common as sharing music and software illegally via peer-to-peer file-sharing services, or as simple as spending far too much time playing games and chatting with friends.

Recent market research suggests that many parents consider online chatting more dangerous than Web surfing. Last year, Microsoft's MSN service shut down its chat rooms in 28 countries partly because of concerns about sexual predators preying on minors. And in a study published by Harris Interactive in November 2003, 24 percent of 550 U.S. teens surveyed said they had been contacted online by a stranger who tried to arrange an off-line meeting.

Meanwhile, the amount of time kids spend online is just as important an issue. A November study performed by the Pew Internet & American Life Project found that almost 70 percent of young users say they would find it "very hard to give up" the Internet, compared with only 48 percent who said the same about television. Computers have become a hub for social activity. And for the most part, it is an unsupervised environment. Many parents go to sleep every night convinced that their kids are sleeping too, while some of the kids are actually chatting online with friends and strangers. And not surprisingly, some kids are also chatting when they should be doing homework.

The Internet has so much good to offer, however, that you can't just take your kids' access away permanently. It's a great educational resource and an essential form of communication today. And the more your kids learn about using the Internet now, the better prepared they'll be for using it in the future.

Parents need to protect their kids online. Just as they want some control over where their kids go and whom they talk to in real life, parents need to establish some rules on where they go and whom they talk to online. Which strategy is best for your needs is your decision. The good news is that the products on the market offer a variety of approaches, so finding the right solution shouldn't be too difficult.

For this story, we tested many types of parental-control tools. We reviewed seven traditional Web-filtering apps, which remain the most popular first line of defense in protecting children from accessing inappropriate content on the Web. We also tested ISPs that provide parental controls, as well as some that offer special browsers designed for children. Home networking gear manufacturers are also addressing these issues, so we looked at two wireless routers that include filtering capabilities and other parental controls—an interesting solution if you have a home network. And we tested four monitoring applications; these apps provide the most aggressive approach, letting you view the sites your kids have visited, read their instant-messaging conversations, and review information about the applications they have used.

Don't be fooled by the category names, though. While each product emphasizes a particular function, most offer a variety of tools. For example, many of the filtering products include time management capabilities, and the monitoring products offer filtering and other parental controls. So we suggest you read through each section to find the solution that best fits your needs.

Our contributors: Sebastian Rupley is a senior editor of PC Magazine. Nick Stam is the director of PC Magazine Labs. Jay Munro is a frequent contributor. Associate editor Matthew P. Graven and lead analyst Laura Delaney were in charge of this story.