Google's new +1 rating system allows users to rate the relevancy of their searches to ultimately help Google improve the search engine.
Google's latest approach to improving search comes in the wake of the StackOverflow/Quora/YahooAnswers craze that continues to make headlines. Rated answers sort themselves up the list of a question, and now so will Google's search results.
This comes in the wake of Google making changes to their algorithm to help weed out content farms, and other websites that skew results to push pageviews over legitimate content. Google's drive to improve search now has it reaching out to its huge userbase to aid it in improving the results.
+1 will only be available to people who have a Google Profile, so that you can only "+1" something once. It also allows other people to see what you've searched on and the results that grabbed your interesting.
The +1 feature is available immediately. Read about the complete release on Google's Official Blog. From there you can choose to create a profile, or upgrade an existing one to support the feature.