I have some long-term business with the United states - it is essentially New York and Washington - and it may be useful for me to have a domestic american mobile number with the data allowance for the smart-phone.
I would like to ask for the suggestions for the no-contract mobile phone services with the data - this is for the repeated professional visits over a two or three year period of the short durations of one to three weeks. Of course for the providers who have the EU phones compatability as I have the dual SIM phone.
(it is useful I add if the service can roam back to the France or the UK for if there is some follow-up calling, but it is not a requirement)
(please if I can ask that the focus be on this mobile question and not other suggestions for alternatives)