Google's 'Plus One' will initially be limited to a mere 2% of Google's English Language users in America. The tool will be very similar to Facebook's 'Like' tool which has become universally used by websites outside of Facebook.
The feature will involve a small icon located next to each search result. Those users that are loggin into their g-mail accounts will be able to share links with friends via a host of Google services. Eventually it is hoped to spread onto Twitter and possibly even Facebook allowing users share with contacts.
The results of user recommendations will potentially influence the ranking of sites in Google's search result listings. It will lead to a more transparent and user based search engine.
Google also announced plans to expand the service to news publishers to ensure popular and relevant news is more visible.