You are looking out for a hotel at a hill station. Hundreds of results are given by Google search. Which one should you opt for? You'd definitely like to go with the one which is recommended by others. Especially if you see your friend recommending it, you are sure to trust his reco and go with his choice(If you don't like the hotel fight with your friend for misguidance...I'm recommending this, not Google :) )! Similarly your likes can prove useful for others. Click +1!
You can join the feature from Google Experiments as of now. Pre-requisite to use +1 is having a Google public profile and login to it. Once you join the experiment +1 button will appear against each search result that google gives. You'll be able to see how many +1s has something already received. If you want to add your recommendation click the +1 button against the particular result. If you've opted to show it publicly your name appears against result with who all have +1ed it. Even if you choose to be private your +1 will be added to the count of total +1s received by a result.
You can view your +1s in an additional tab in your profile. You can set the option of making your +1s public or private by editing the profile.
This feature of Google is viewed as its attempts to go 'social'! Whatever the strategy might be, as long as users benefit from this social feature we have our +1 to this feature!! What is your say?