Google's Urs Hölzle gave a keynote presentation titled "Google: How We’re Making the Web Faster" at the Velocity 2010 conference on 23 June 2010. http://www.datacenterknowledge.com/archives/2010/06/23/google-how-were-making-the-web-faster/
[Ironically, that page may be slow.]

"This year the search giant is showcasing how it is using its software, servers and infrastructure to create a faster Internet – and calling on site owners to join the effort."

"'Speed matters,' said Hölzle. 'The average web page isn’t just big, it’s complicated. Web pages aren’t just HTML. A web page is a big ensemble of things, some of which must load serially.'"

"He said Google also could serve pages faster if it had more information from DNS servers about an end user’s location."

"Google is also using its own data center infrastructure to offer speed enhancements for web surfers and site owners. An example is Google Public DNS, which allows anyone to use Google’s distributed system of DNS servers. 'We saw that DNS performance was often a contributor to slowness,' said Hölzle."

I wonder if determining a user's location is one reason why Google is providing a DNS service.

"Building faster sites can matter in a site’s Google ranking, Hölzle noted, referencing a recent change in which Google considers site loading speed as a factor in its ranking algorithm."

"'If your web site is slow, you’ll drop down in the rankings, because we know users don’t like low sites' he said. Page speed isn’t as important as other factors (like content relevance) but can server as a deciding factor between two sites with similar rankings, Hölzle said."

The earlier quote says speed is a factor in ranking, but the later quote says that speed is a factor in deciding between sites [pages] with similar rankings.

Velocity 2010 conference: http://en.oreilly.com/velocity2010

> I wonder if determining a user's location is one reason why
> Google is providing a DNS service.

How would providing a DNS service be used to determine a user's location? (I'm not disputing, just asking).

Are you suggesting that Google could track the domain names a user accesses, and try to work out from those where the user is located?

For ordinary geolocation, you don't need to provide a DNS service.