Google announced the launch of Google SearchWiki yesterday. Among the features of this new search utility is the ability for you make notes about a site, move it in your search results and eliminate it from search results all while you are signed in to your Google account. Here's a YouTube video announcing the service
You can see what Seth Godin has to say about the new Google Search Wiki with his recent blog posting "Google gets jiggy", i.e. people gaming the system and more attention to Google by searchers.