Loyalty cards can quickly clutter your wallet. Here's an easy way to convert them from full-sized cards to keyring-friendly alternatives.
Since most of these loyalty cards work off a bar code instead of a magnetic strip, Instructables suggests cutting out just the bar code strip, punching a hole, and putting that on your keyring. You may need to write the store name on the opposite side of the card if it isn't visible. Hit the link for step-by-step instructions.
Keychain Loyalty Cards [Instructables]