At last week’s event, Apple announced that iOS 8.1 would be released today. The iOS 8.1 feature with the biggest potential impact is, no doubt, Apple Pay. From Apple’s official Apple Pay page:

Now paying in stores happens in one natural motion — there’s no need to open an app or even wake your display thanks to the innovative Near Field Communication antenna in iPhone 6. To pay, just hold your iPhone near the contactless reader with your finger on Touch ID. You don’t even have to look at the screen to know your payment information was successfully sent. A subtle vibration and beep let you know.

If you own an iPhone 6 or 6 Plus, you are good to go. If you own an iPhone 6, iPad Air 2, or iPad mini 3, you can use Apple Pay (via Touch ID) to pay within apps.

UPDATE: A number of people have said that the iPhone 5s should be a good to go device for app purchases. If you scroll to the bottom of the Apple Pay page, you’ll see a chart that shows iPhone 5, 5c, and 5s as being compatible with Apple Watch, but not compatible with in-app pay. The issue is the lack of the NFC chip and secure element.

And, of course, once the Apple Watch is released, you’ll be able to use your watch (combined with your Touch ID enabled phone) to pay:

You can pay with Apple Watch — just double‑click the button next to the Digital Crown and hold the face of your Apple Watch near the contactless reader. A gentle pulse and beep confirm that your payment information was sent.

If you haven’t read this already, this article talks you through the mechanics and safety of Apple Pay.

Apple Pay will be limited out of the gate, limited by hardware (as detailed above), and limited by merchant adoption. Best to think of this as the start of a new era. Apple has hit the ground running, with Visa, MasterCard, and American Express signed up, along with a good number of bank card providers. If your card participates in Apple Pay (you likely got an email from them if they do), your first step will be to add that card to your Passbook app.

According to Apple, there are more than 220,000 stores that have the contactless NFC readers in place and are set up to take Apple Pay today. I wonder if today’s iOS Apple Pay release will spur a new round of iPhone 6 purchases. I also wonder if McDonalds is going to see an unusual run of business today from people testing their new Apple Pay-enabled phones.