Google empowers users to edit search results
Found on PhysOrg on Thursday, 20 November 2008

Hoping to give its search engine a more personal touch, Google now lets users reshuffle results so their favorite Web sites get top billing and disliked destinations get discarded the next time they enter the same request.
Users will have to have a personal login to take advantage of the editing feature.
The decision to let people tinker with their results is a tacit acknowledgment that not even Google's seemingly omniscient search engine can possibly divine which Web sites will appeal to specific users.
So instead of simply letting users flag spam websites without being logged in, Google once again requires you to give them a constant history of your search queries.