[cflsystems]

The easiest way would be to use membership. It will require you to modify some code but I think at the end is the best way to do this. This will only work if you do not use memberships though. You can create 2 membership groups - say North America and World. Assign payment method CC to North America membership and payment method phone to World memberhsip. Now you need to modify register.php to auto assign membership to every customer when creating profile based on billing address (or shipping, whichever you want to use). XC should pick it up from there showing correct payment method(s).

This is untested, just an idea, but it should work