What does the Google Caffeine Compare do?
Google currently lets people pre-test their new enhances search index technology available at "www2.sandbox.google.com
" (Codename: "Caffeine
"). This tools lets you easily compare caffeinate results with de-caffinate results (a.k.a. plain old Google). Just type and search as usual. More info on Matt Cutts blog
and on the officla Google Webmaster blog