According to the official blog post ( http://googleblog.blogspot.com/2011/02/advanced-sign-in-security-for-your.html http://googleblog.blogspot.com/2011/02/adva

According to the official blog post ( http://googleblog.blogspot.com/2011/02/advanced-sign-in-security-for-your.html http://googleblog.blogspot.com/2011/02/advanced-sign-in-secu... ), this will be rolled out over the next two days.