download google authenicator
in the first place you can NOT accidentally add an authenticator, you have to purposefully add it. This means that you probalby got hacked sometime and the hacker put an authenticator on it so he would have more time to do his thing. Call Blizzard Billing. They are the only ones that can help you.
It's free with a Google account. Google accounts are also free.
The purpose of an authenticator is to provide an extra layer of security
No. You only have to pay for your monthly subscription, the expansions, and extra stuff you might want to buy such as ventrilo, in game pets, authenticator(You can download a free authenticator if you have an ipod touch or iphone etc), head set, etc.
Google calendar is actually free to use for individuals. It is accessible from your Google homepage and can be a useful addition to a physical diary.
revealing an authenticator over the phone
An authenticator is a person who authenticates something - who proves something to be authentic - or a condition or feature of a thing which makes it authentic.
Yes. Google calendar is free to use.
No, it is free to use!
Skype is similar to Google Voice and there is a free app.
The Google Earth plugin is free. It can be downloaded with the free version of Google Earth (they're bundled together) or by itself from Google's website (see link below).UPDATE: Google Earth Plugin has been deprecated as of December 12th, 2014.