You may have noticed a few additional buttons and icons your Google search results lately. Google has rolled out a feature, called SearchWiki, that lets you rate up good items in your search results and remove irrelevant results. You have to be logged in with a Google account for these to show up.
Your ratings will be visible to others although they will not impact the order of others results. This provides a way, approved by Google, to modify your personal search results. It will be interesting to see if Google will use this input to modify overall search results now or in the future.