Google is in process of introducing +1 button where user can easily recommend your content from the search results pages as well as from content pages.
Quote:
Originally Posted by Google
+1 is a simple idea. Let’s use Brian as an example. When Brian signs in to his Google Account and sees your site in the organic search results on Google (or search ads if you’re using AdWords), he can +1 it and recommend your page to the world.
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Quote:
Originally Posted by Google
+1 could increase both your quality and quantity of Google search traffic.