USA ESTA Visa Waiver Official Site
Official Site for USA ESTA Visa Waiver Program:
International travelers who are seeking to travel to the United States under the Visa Waiver Program (VWP) are now subject to enhanced security requirements and will be required to pay an administrative fee. All eligible travelers who wish to travel to the U.S. under the Visa Waiver Program must apply for authorization and then pay the fee. Valid Australian passport holders may use this website. Other passport holders will need to check either with myself or the consulate directly in order to ascertain whether and which visa is applicable. Please feel free to ask if you require assistance with visa's.
Please be aware of alternative USA Visa ESTA application websites as they may charge considerably higher amounts. It is recommended to use this official USA Customs and Border Protection website.