Last, Wednesday I showed you kid-friendly search engine Quintura, and we also looked at the kid-friendly Web browser KIDO'Z. Today it's time for the big gun: OpenDNS. It's a server-level filter that promises to protect your kids from online violence, pornography, phishing, and more.

And it works. To use OpenDNS, you simply make a few small tweaks to your home network router. Don't have one? You can make the necessary adjustments right on your PC. In both cases, the result is one small but significant behind-the-scenes change: Your Internet access gets routed through OpenDNS' servers rather than your ISP's.

What makes OpenDNS servers so great? Simple: They block inappropriate and malicious sites. You don't have to install or program any software or set any permissions; OpenDNS does the heavy lifting.

You can, however, choose one of five filtering levels, the highest of which blocks everything from adult-related sites to video-sharing sites to "general time-wasters." (They should call that one, "This PC is for Homework Only.")

There's also a Custom option that lets you choose from dozens of filtering categories. That's handy if you're okay with, say, Business Services and Politics, but want to block stuff like Alcohol, Gambling, and Weapons.

Amazingly, OpenDNS is free. I'd go so far as to say it's the single best solution for parents seeking to protect their kids from inappropriate Web content. (It's also a pretty killer solution for small businesses, according to PC World's David Strom.) Highly recommended for households with toddlers, tweens, and teens alike.