Earlier the better, but I'm pretty sure it's automatically done at application. Check for biometric passport requirements as I gather that's changing.

Cool thanks Flash, got a Biometric, can you imagine turning up and being denied entry for that???

For an ESTA application you need your address you will be staying at during your visit. So if you have your hotel booked you can apply for the ESTA.

However, they don't seem to perform any actual checks on what you put on your application so you could just put a random hotel address........

Address is largely irrelevant. My current ESTA has a hotel in Atlanta as the address, as that was held first trip on this visa. Have been countless times since, all to other addresses. Back to Atlanta today, as I happens!

I did mine 11pm the night before a 9am flight as I didn't realise I needed one 😳 . Not advisable but didn't make any difference

Getting an ESTA is no biggie.

Not having biometrics will most likely see you refused entry.

It's approved pretty much on the spot. Unlike the Australia e-visitor pass (grrr!).

Probably worth mentioning as well, make sure you go to the official site. There's any number of third party sites (or at least, there was when I last looked) who will happily do exactly the same application for you only with a huge mark-up.

Yup, we landed at JFK last week, and witnessed someone trying to gain entry without a biometric passport..
You could hear the shouts from the far side of the terminal!

All done thanks, dont remember it being quite so onerous 18 months ago, now valid until 2018.

3 weeks I will be in Denver stuffed full of Voodoo Donuts 😆

Yup, we landed at JFK last week, and witnessed someone trying to gain entry without a biometric passport..
You could hear the shouts from the far side of the terminal!

They shouldn't have been allowed on the plane, the US will fine the carrier the costs of deporting them.

For an ESTA application you need your address you will be staying at during your visit. So if you have your hotel booked you can apply for the ESTA.

You do not, "UNKNOWN" is perfectly acceptable in those fields.

They recommend at least 72 hours before travel if you're cutting it that fine. I'd allow a couple of weeks.

Lots of news coverage recently about Brits being refused at check-in for not having a biometric passport. ESTA you should do in good time, the only reason to wait is its a fixed term (3yrs?) so by delaying you are gaining time for any future trip.