Google announced that third party developers can now enable users to sign in using their Google+ account to their own applications. Twitter, Facebook, and many others have this and Google+ just added it yesterday.
Google is saying theirs is better because it is easier and much more secure to use than others (i.e. Facebook). Danny Sullivan asks if it is really more secure and comes up saying that it really is not.
Still, Google says this option "prohibits social spam". Here is a video on how it works:
Why is Google adding this? They want more users to use Google+, they want more user data.
Will you add this to your site?