Owing to my wife’s uncanny ability to either destroy or lose cards of all sorts in a staggeringly short amount of time, I was happy to come across this webtool that will let you create a single club card that duplicates the bar codes of up to eight individual cards. For my purposes, it is also handy for creating duplicates of existing cards. I can only vouch for the fact that it made a perfect working copy of a Kroger card (your mileage may vary).
The same old thing with a new twist (aka my personal infocloud)