Search giant Google has begun public testing of a new +1 feature in search results which allows adds social recommendations which can influence other users' search results.
The experimental feature currently needs to be opted in to specifically and then adds a +1 button next to search results.
The amount of people that have +1'd a link, will be visible and search results will be prioritised if the Google account holder's friends have also +1'd the link.
Google said that after opting in it may take some time for the button to appear. You can join the +1 button experiment on this Google Labs page.
Below is the usual Google introductory video video for the feature: