Thought you may find the below handy:-
Not sure if you are aware but travel to the USA now requires everyone to apply online for their own individual ESTA (Electronic System for Travel Authorisation) to be entitled to enter the USA. You will no longer be able to travel using the current visa waiver program that you fill out onboard the aircraft.
From September 2010 there will be charge of £25 to apply for each ESTA or renew an existing one.
Once approved, an ESTA is valid for multiple entries over two years – or until the holder’s passport expires.
To apply, click on this link:-