Google is starting to roll out the +1 button, starting with google.com, if you default to a localized search page like google.ca, you will see it soon. We liken the +1 button to the Facebook Like button, use +1 to give something your public stamp of approval, so friends, contacts, and others can find the best stuff when they search. Get recommendations for the things that interest you, right when you want them, in your search results.
Your +1’s are public. They can appear in Google search results, on ads, and sites across the web. You’ll always be able to see your own +1’s in a new tab on your Google Profile, and if you want, you can share this tab with the world.
Google has plans for a +1 button that can be used on sites outside of Google, just like the Facebook Like button.
To use the +1 button you will need a Google Account. This is be the barrier to general adoption, not everyone has a google account, nor do they use it while searching. Why would I sign-up for a Google Account just to use +1, when Like is almost everywhere I want?
Great idea, that has much more potential than the Like button, but it will really need wide adoption to truly be useful and successful, but the impact to search and your ranking could be dramatic!