You may or may not have noticed some small, light-blue buttons with a “+1” inside them showing up next to your Google search results lately. Welcome to +1, a new social feature Google has slowly been rolling since an announcement on March 30. If you don’t have any idea what I’m talking about, you can opt-in to the feature in Google experimental, though the feature will eventually be visible to everyone.

So what is this new button? +1 is Google’s answer to the Facebook “Like” button. When you +1 a search result, you are essentially broadcasting to your Google social network (contacts from Google Chat, Talk, My Contacts, Reader and Buzz) that you recommend the search result. When someone in your network performs a relevant search, they’ll see your profile pic below the result, indicating you +1’d it.

What implications does this have? Myriad, but I’ll just mention a couple that may be relevant to site owners. For one thing, the number of +1’s a link gets are likely to begin to influence searchers’ clicks. If a couple of people in your network (or a large number of people outside your network) have recommended a link, you’ll probably be more likely to give it a chance. And +1 data will also begin to influence Google’s algorithm directly. Secondly, paid advertisers will find that their ads now have a +1 button on them. Don’t worry! A click on the button won’t cost the advertiser anything, and Google says that they anticipate increased click-through rates on ads that have been +1’d. You’ll also be able to see data on how many +1 hits your ad has gotten.

It’ll be some time before we see how well this social experiment works out for Google. They’ve had some disappointments in the recent past, so they’re likely to take it slow. Some in the SEO world are skeptical because they say the system can too easily be manipulated by interested parties. However, Google has enough information about most of its users to tell whether they’re legitimate accounts or fronts for those looking to manipulate page rankings.