On Thursday, the don’t-be-evilest company on the Internet unveiled Google Public DNS. DNS is a detailed subject, but the short version is this: When you tell Safari to load up Macworld.com, your computer first needs to figure out just what server(s) that name refers to. A Domain Name Server is like a big phone book, so that your computer can look up Macworld.com, and find out that it should load the Webpage hosted by the server at, say, the IP address 184.108.40.206.
If you’re like most people, you’ve probably never given your DNS a second thought; your ISP handles DNS lookups behind the scenes. But the nerdier set, along with the slower-default-DNS-servers set (and I’m a part of both) have turned to services like OpenDNS for faster, more reliable, and more customizable DNS services.