Thought that I might ride to N. Carolina for the K Bike Camp Out. Rather than using my Canadian cell phone and get dinged big time for useage out of country (like last year), I thought I'd buy a US throwaway cell with a card for minutes and then use my 1-800 calling number. Do you have any recommendations as to which carrier is better than another or should I just hit the first Walmart and buy a $10.00 phone and a card with minutes?