What you are proposing is the type of business that someone-who-shall-always-be-known-as Atlas would proffer. A POS using mag-stripes is so 1980's. Casascius is developing one. http://en.bitcoin.it/wiki/Casascius_Bitcoin_POS_system
A discussion thread is here:
http://bitcointalk.org/index.php?topic=46366.msg552374#msg552374