On March 31 Chile joined the Visa Waiver Program (VWP).
Qualified Chilean nationals traveling to the United States for business (B-1) or pleasure (B-2) will no longer require visas for travel if they meet all requirements for visa free travel. See http://london.usembassy.gov/niv/vwp.html.
If you are a Chilean passport holder and are thinking of taking advantage of the change in U.S. immigration law, please check your eligibility for the VWP carefully. If you do not fulfil all of the requirements, you will be required to apply for a visa before traveling to the United States.
And remember, if you are qualified, and are entering the United States by air or sea carrier make sure you register under ESTA on the official U.S. government website a thttps://esta.cbp.dhs.gov before traveling.