Since I was taken by surprise last week by a new rule issued by the U.S. Customs and Border Protection, I thought I would take a moment to mention it here. CBP now requires all visitors to the United States from any country participating in the Visa Waiver Program to fill out an online application before you can enter the country. It is called the Electronic System for Travel Authorization (ESTA), and it became mandatory starting January 12th. It is short, easy to fill out, and good for about two years after you apply (if none of the information on the application changes). Here is a useful fact sheet. Just to be clear, this does not refer to Americans planning to travel abroad, but to foreign visitors to America. If you have family or friends visiting you in America, be sure to let them know in advance about this new law!