I am in the process of redoing our billing interface and I am incorprating some of the other non standard billing options for countries that dont primaraly use credit cards.

has anyone had a good sucess with charging systems like

sms
per min phone billling ( the dialer type )
bill me later / charge me later invoicing
900# billing

any words of caution against these options?

I dont intend to confuse the surfur by displaying all of these options , rather use geo select to show the one relevent to the country / area they are coming in from