Walgreens
Apple is expected to announce its mobile payments platform along with new iPhones on Sept. 9. The new iPhones are said to have near-field communication (NFC) chips that can communicate with point of sale terminals when you tap the phone against them.
Apple is also expected to announce a new wearable computing device, the so-called iWatch, on Sept. 9. That gadget is also said to have NFC and may also be used for payments, according to Brian X. Chen of The New York Times. NFC could also be used to pair the iWatch with your iPhone.
Assuming all these reports are true, you can expect several more major retailers to come out in support of Apple's payments system on Sept. 9.