Edit your /etc/resolv.conf
208.67.222.222
208.67.220.220
OpenDNS is the world’s leading provider of Internet navigation and security. Make your network safer, faster, smarter and more reliable without the cost and complexity of traditional security services. Some feature is SmartCache.
SmartCache
OpenDNS’s proprietary DNS caching technology finds and locates the last known good IP address for Web sites that are experiencing difficulty, making Web sites that are down for the rest of the Internet load for OpenDNS users.
For more detail see http://opendns.org