Google is always experimenting with new features aimed at improving the search experience. Their recent experiment is called “+1” button which will be integrated next to their search results.
One must have a Google Profile to use this feature. When a user click on the +1 button their Google profile gets associated with that link in search, on ads, and across the web and this shows up in their profile activity on Google Profile page.
Watch the video below and find out more on http://www.google.com/+1/button/