debit cards/credit-2 different ones-that way if one gets "eaten" by the atm -and I've seen it happen(and its a huge hassle getting it back) I will have a back-up .....
I always carry some emergency cash too.....one main reason is-if the electricity goes out (and it does) you cant access ATMs...or (and this happens alot too) if the ATMS run-out of $$$....
