Last week, a new toolbar began appearing on Google for user and some took it as evidence of the ever-elusive "Google +1" or "Google Me" social network. Today, Google explained the appearance of this part of the bar as a simple method for users to keep track of what identity they're using as they browse online and use Google services.

In a blog post entitled "The freedom to be who you want to be..." the company explains that the toolbar help ensure users "know exactly what mode they're in when using Google's services."

According to Alma Whitten, director of privacy at Google, there are three basic forms of identity a user can assume when using Google's services and they should be aware of which one they are assuming at any given time.

We've been thinking about the different ways people choose to identify themselves (or not) when they're using Google--in particular how identification can be helpful or even necessary for certain services, while optional or unnecessary for others. Attribution can be very important, but pseudonyms and anonymity are also an established part of many cultures -- for good reason.

When it comes to Google services, we support three types of use: unidentified, pseudonymous and identified. And each mode has its own particular user benefits.

Whitten explains that unidentified is not fully anonymous, but rather tracked by IP. Nonetheless, Google doesn't "link that information to an individual account when you are logged out." Pseudonymous allows users a consistent identity, but "one that is not linked to their offline self." Identified is just that. It's for times when "you want to share information with people and have them know who you really are."

"Equally as important as giving users the freedom to be who they want to be is ensuring they know exactly what mode they're in when using Google's services," writes Whitten. "So recently we updated the top navigation bar on many of our Google services to make this even clearer. In the upper right hand corner of these Google pages, you will see an indicator of which account, if any, you are signed into. "

Could this be a step in the direction of the so-called "Google +1"? If, by that, we mean a social layer in Google, then certainly identity has something to do with a "social layer." Beyond that, it seems like a responsible move by the Big G to make sure users realize how the actions they're taking could be connected to their Google identity.