I will be travelling to the Bahamas in Oct and then going to Las Vegas at Xmas. In the New year I will be returning to the Bahamas for 3 months. Do I need a visa or can I just move in and out of the USA using the visa waiver programme and do I need to apply each time I travel. Thanks
To add to the previous answer, once you succesfully apply for an ESTA as part of the Visa Waiver Programme then it lasts for 2 years and is valid for multiple entry to the USA.
ESTA is effectively the green form that you used to fill out on the aircraft, online. Except that you only do it once and it lasts for multiple entry for two years or until the the end of the passport validity if sooner. It`s a massive improvement on the old system.