Facebook scammers are once again trying to pique your curiosity by using suggestive terms and promises of a Google + invite. Just like with previous scams, they are leveraging Facebook to target ignorant victims.
This version says something along the lines of "Google+ - Get Invite" followed by a link and then a description like "Unoffical Fan Page." There's even the text "Page: 80,000 people like this" which increments every time more users fall prey to the scam. According to Sophos, if you visit the page, you are asked to allow a third-party application to access your Facebook account. Then you're told to spread the content to your Facebook friends and family by Liking the Page. Last but not least, you are then encouraged to invite as many of your friends as possible to also sign-up for the scheme.
At this point, you have still not seen a Google+ invite, and you never will. What you have done, however, is given a third party application access to your Facebook profile and told your friends to do the same. As a result, the owners of the application can then post spam messages, distribute further scams, steal your personal information, and post in your name.
As I've recommended before, if you see a scam like this one, report it. Then go check your own wall to make sure you're not spreading the scam; the sooner you clean it up and unlike the page, the better. You can even contact Facebook Security if you'd like to.