I've been trying OpenDNS this weekend and it seems to be quite fast. It's extremely easy to set up using their clever instructions for any type of router or computer, and it starts working instantly. Usage of this service has been steadily growing over the past few months.
For those who care to know, DNS (Domain Name System) resolution is a service usually provided by your ISP (Internet Service Provider). When you type in a site name in your browser, the first thing it does is to query your ISP's DNS server to find out the IP address of the computer that hosts that site. Once it has done this, it can load the page. OpenDNS claims to shorten the time that this IP address lookup takes by having a huge cache, meaning that they usually can return a result to you without having to ask another nameserver, which would take more time. In addition, they have servers at the main crossroads of the internet. Whenever you see "Looking up (example).com" in the status bar of your browser is when DNS resolution is occurring.
So maybe give OpenDNS a try, if you have access to your network settings. You may be pleasantly surprised at how fast your internet goes. They also claim to offer phishing protection and will block known phishing sites. The service corrects spelling errors, too, so if you type in something like "google.co" instead of "google.com," you will be instantly redirected. Pretty cool!