Matt Cutts, a Ph.D in Computer graphics, is the Head of Google’s Webspam Team. He was instrumental in launching SafeSearch, Google’s family filter that helps keep the web safe for children.
This Search engine optimization evangelist is Google’s spokesperson for Search quality related issues. A regular at all major Search Engine conferences, Matt Cutts tirelessly travels to meet webmasters across the world, understanding issues and reporting them back to the Google Team to help find solutions.
A subject matter expert on Search Engine Optimization, he often offers his advice and clarifies major SEO and search isssues on his personal blog. Matt Cutts Blog on SEO
Often he also pops up at Google Webmaster Blog
You may also be interested in reading his interviews. Google Webmaster Blog