DNS plays a key role in enabling web users get to their target resources, as often times, popular resources exist in different locations. It serves like a phone book for the internet, thereby converts readable domain names into an IP address that PCs can connect to. For instance, when a user tries to connect to a resources that exits in 50 different locations across the world, definitely you want prompt response and fastest or least congested location automatically.
But, until now, figuring out the location that is nearest to you is not possible with DNS alone. However, now using OpenDNS or Google Public DNS, and using a service provided by one of the participating networks (CDNs) in the Global Internet Speedup Initiative a truncated version of your IP address will be added into the DNS request. And the internet service will use this truncated IP address to make a more informed decision to connect you to the most optimal server.
This intelligent routing will ensure among other things that users have a better internet experience with lesser latency and faster speed.
Google's interest into positioning web apps to effectively take-on desktop apps has indeed found a resting place, albeit perhaps, making the internet faster will invariably benefit all web users alike.