Re: AGAIN?!?
I used to do a lot of travel for a big American bank.
The advice was always take two cards, two providers, two different networks, perhaps a visa debit card and a mastercard credit card from different banks.
This was great advice and I would recommend in normal life too.
My job is in IT and I would not trust any deployment to be permanently available for reasons both in and outside my control.
Quote from Red Dwarf along the lines that "Computers are not Infullible" comes to mind.