My personal user stylesheet to get rid of focus outlines on non-form elements because I don't personally need them for accessibility.
Don't ever do this in your site's stylesheet because you're putting disabled users at a disadvantage. Do put this in your own user stylesheet if you hate the focus outlines in Gmail, Google Groups and countless other web apps.
See also: http://www.outlinenone.com/
For Chrome on Mac, this goes in
~/Library/Application Support/Google/Chrome/Default/User StyleSheets/Custom.css