Google Improves Security With Help From Your Smart Phone
As your Google account becomes increasingly important Google have announced a new (optional) technique to secure your account using your mobile or smart phone.
Google’s system doesn’t require a physical keycard. Instead, it relies on your mobile phone. First, you need to activate the optional feature from your settings page (again, this is only available to certain Google Apps customers at first). Then, when you go to sign in to your Google account, you’ll first be asked to enter your password as usual.
Google Is Making Your Account Vastly More Secure With Two-Step Authentication.