The +1 button is yet another social feature of Google Search as a way for users of telling they recommend a particular webpage discovered after doing a search. The new feature would then help Google identify which of among the number of links from the search results are relevant based on the number of +1’s, thus delivering even more relevant results to other users searching for same queries.
Here’s a video showing how Google +1 works.
Google says they’re already rolling the new feature starting in English in Google.com; however, you may also opt-in ahead of the schedule in your location by joining the experiment at Google Labs.
Could this be Google’s answer to Facebook “Like” or “Recommend” features? Well, I guess so.