Here is a significant development from Japan:

“A system called “Town Pocket” will be deployed at 153 shops including 109 apparel stores, 14 cafes and restaurants, 10 hair salons, 13 accessory shops, and 7 shoes/sports shops. All these shops will install an RFID reader device (photo) to which customers show their wallet phones in order to “bookmark” stores. People who don’t have wallet phones can also use QR codes (for camera phone users) or a special email address (if you send an empty email message to this address, you can bookmark the store).”