OpenDNS (
http://www.opendns.com/) and Google Public DNS (
http://code.google.com/speed/public-dns/) are two DNS (Domain Name System) resolution services that libraries or patrons can use for free (OpenDNS has paid versions, too). OpenDNS has been around for some time, while Google Public DNS was just recently announced. Information that can be found on the links to the two services offer explanations of what they do and why it may be advantageous to use over your present DNS service.
