The present invention provides a system and method for facilitating a RF transaction using a secondary transaction number that is associated with a user's primary transponder account. The user provides the secondary transaction number, often with limited-use conditions associated therewith, to a merchant...http://www.google.ca/patents/US20050077349?utm_source=gb-gplus-sharePatent US20050077349 - METHOD AND SYSTEM FOR FACILITATING A TRANSACTION USING A TRANSPONDER
