The U.S. has introduced a new Electronic System for Travel Authorization (ESTA) program which will affect business visitors travelling to the U.S. who are citizens of countries under the Visa Waiver Program ("VWP"). The list of VWP countries is here: VWP List of Countries 

Under the proposed ESTA, foreign nationals wishing to visit the U.S. under the VWP will first need to register under the ESTA. This program is supposed to come into effect by January 12, 2009. Generally, a positive determination under the ESTA will remain valid for two years and therefore may be used for multiple visits to the United States. 

The ESTA site is up and running so those affected by this new process can sign up now. 

The ESTA program does not affect Canadian citizens as Canadians are visa exempt. However, Canadian employers that have foreign nationals or permanent residents of Canada working for them who have citizenship in countries that come under the U.S. VWP will need to make sure that their employees apply under the ESTA in advance of any need to travel to the U.S. for business visitor purposes. The on-line ESTA sign up tool may be accessed via the link below.

FAQs about ESTA