Google Plus One Widget for WordPress
Google Plus One Widget is a WordPress plugin by karolsojko that Adds the new Google “+1″ button on single posts pages, page type pages and homepage under post titles.
Google +1 is a social feature for Google’s search service adding a one-click button to allow users to recommend sites and share those recommendations with their friends.
Appearing as a small icon next to each search result and text ad, logged-in users can share their recommendations with contacts through their Gmail address book, Google Reader and Buzz contacts and, eventually, Twitter contacts.
Download and info: http://wordpress.org/extend/plugins/google-plus-one-widget/