The old forms were filled out en route
A new online entry system to the US, which will be compulsory for British tourists from January, will protect their privacy, say US officials.
Visitors from countries which do not need visas must register details three days in advance under the electronic system for travel authorisation (ESTA).
Outlining the scheme at the US Embassy in London, officials said there would be safeguards to keep details private.
The system will be valid for all visits to the USA for a two-year period.
The new online registration scheme replaces the green I-94 forms that people on short term visits to the US have previously filled in on the flight and handed to customs on arrival.
Part of a tightening of the US visa waiver programme, it will be compulsory for all visa-free travel from 12 January 2009.
It is intended to boost security by allowing screening of visitors before they travel.
But Michael Restovich, the US Department of Homeland Security attache, said the system would also speed up entry into the US for many visitors.
"All the privacy concerns have been addressed and safeguards put in place to ensure that only people who need to see the information do so," he said.
Visitors should learn almost immediately if they are allowed into the US and airlines will be responsible for ensuring the ESTA forms are in order.