bplay.com has it enabled as a payment option
so does futureshop mobile site.
its integrated into the site to access the device database storing the info to fill in the required fields, be it log in information, frequent flyer card, credit card, etc..
to check it out in its full glory go to bplay.com on ur device
OR
DL the futureshop mobile store application
blackberry.com/futureshop
all information is stored on ur device, is password protected(like password keeper) and is AES encrypted
and if youre a super geek
here are the API docs:
BlackBerry - Product Manuals and Guides