What I think Society is trying to say is that this question isn't exactly new! Here's a summary of the information you'll find in those links:
1. The USA doesn't recognise the UK's Rehabilitation of Offenders Act. So no conviction is ever regarded as 'spent'.
2. The rules on the US embassy website state that anyone who has ever been arrested (even if totally innocent) or convicted of an offence is ineligible to enter the USA under the Visa Waiver Program and consequently MUST apply for a visa).
3. The USA's Immigration & Nationality Act AUTOMATICALLY bars anyone who has committed an act of 'moral turpitude' from entering the USA. (There are minor exceptions but they don't apply here). So, in the first instance, the US embassy MUST refuse to issue you a visa.
4. Under those circumstances your application can then be forwarded to Washington as an application for a 'waiver of permanent ineligibility'. If that happens, the MINIMUM time before you'll hear whether you'll get a visa is 5 MONTHS. However it can be much longer. (Someone on AB waited 15 months before being refused a visa because of two offences of driving with no insurance).
5. The USA has no direct access to UK criminal records, so some people simply 'forget' about their convictions and attempt to enter the USA under the Visa Waiver Program (with an ESTA).
6. Several people have posted on here to state that they've entered the USA without any problems, with undeclared criminal convictions, by that route. However there have been reports in the travel press of some people who've been 'found out' having some very unpleasant experiences upon arrival in the USA.
Chris