Google debuted its version of Facebook’s “Like” button Wednesday. Dubbed “+1,” it lets users give a quick nod of approval to a search result or Google ad — and eventually to any page or site on the web that chooses to include the button.

The so-called +1 button builds on Google’s forays into integrating social recommendations into search. For instance, if you connect your Google and Twitter account, any search result that has been tweeted by someone you follow will include a small photo of that person (screenshot above). With +1, anyone with a Google account can register a vote of approval, which can then be seen by other searchers.

Google explained in a blog post Wednesday how the new social voting feature would work in search:

When you do a search, you may now see a +1 from your slalom-skiing aunt next to the result for a lodge in the area. Or if you’re looking for a new pasta recipe, we’ll show you +1’s from your culinary genius college roommate. And even if none of your friends are baristas or caffeine addicts, we may still show you how many people across the web have +1’d your local coffee shop.

If you vote up an ad, the votes will display on the ads served by Google around the web, but the vote currently won’t change ads’ positioning or cost.

So far, Google is not using the votes as a way to reorder search results — most likely because that would lead to spammers exploiting the system.

For now, the buttons are limited to results on a webpage and Google ads, but Google says it will soon have a plug-in so that you can +1 a website after you’ve clicked through a search result or a specific article after you’ve read it.

Facebook’s version, the Like button, is nearly ubiquitous on the web, and clicking on that button shares the item on your news feed, spreading content through webs of connections.

In either an ironic or intentional bit of timing, +1 comes the same day that Google settled an FTC complaint over Buzz, its Twitter-like service that ran into a buzz saw of complaints over how information from Gmail easily became public on a Google profile for those who didn’t take the time to read the sign-up prompts. According to the settlement, Google will have an outside privacy audit biennially for the next 20 years, and won’t use personal data it collected for one purpose for another without permission.

Like Buzz, +1 requires users to have a Google profile or to update its settings to allow the +1 service. The +1 votes are not, however, made public. You can view and edit your own votes on your own Google-profile page.

Google is rolling out the feature slowly to users of Google.com in English, but those who are impatient can start seeing the button immediately by joining the “test.”

There’s also no way yet for users to automatically publish their votes through Buzz or Twitter or Facebook, but those are likely coming if Google can get permission to do so.

The +1 feature’s introduction hints at Google’s strategy for breaking Facebook’s tight hold on users’ identities and how they share information. Instead of building a full-on competitor to Facebook by, say, redoing Orkut, Google looks to be trying to slowly get users to create a public identity page. Then it can create services that work with that page, until users find — like a frog in water slowly boiling — that they are actually a part of a social network Google has slowly built around them.

I “+1? that strategy over trying to get Facebook users to go cold turkey, however exciting a big announcement and showdown would be.