Earlier today, Apple posted two support documents detailing frequently asked questions about Apple Pay and the security and privacy of the service.

From the FAQ:

When I’m paying in a store using my debit card in Apple Pay, should I choose Credit or Debit on the terminal?

When presented with this choice, we recommend you to choose “Credit” to get the most consistent Apple Pay experience. Choosing “Debit” may not always work successfully with some older merchant payment terminals and backend systems.

And about security:

When you pay using Apple Pay in stores

Paying in stores that accept contactless payments with Apple Pay uses Near Field Communication (NFC) technology between your device and the payment terminal. NFC is an industry-standard contactless technology designed to work only across short distances. If your iPhone 6 is on and it detects an NFC field, it will present you with your default credit or debit card. To send your payment information, you must authenticate using Touch ID or your passcode. No payment information is sent without your authentication.

MacRumors has a list of the retail stores that have begun accepting Apple Pay in the US today. Apple has also launched an Apple Pay section (currently on the front page of the US iPhone App Store) showcasing iOS apps that have been updated with Apple Pay support, including the Apple Store app.

Apple Pay, the company’s new payment system for iPhones and iPads, rolled out in the US today with iOS 8.1, and Kyle Russell has a nice demo video of the feature in action:

Holding my thumb to Touch ID and my phone to the payment terminal, it took about a second and a half to register at Walgreens and the same amount of time at McDonald’s. Don’t expect it to change the entire experience however: you still have to sign for the amount shown at the drug store and get a receipt to show to the cashier when picking up your order at a fast food joint.

Jason Snell shared a similar experience at Six Colors:

I pulled the iPhone 6 out of my pocket and before I could even move it closer to the payment terminal—newly festooned with a Now Accepting Apple Pay tag—Apple Pay appeared on my phone and asked me to verify my purchase via Touch ID.

Below, a few demo videos from YouTube as well, showing the simplicity of Apple Pay with contactless payments.

Yoni Heisler has an in-depth overview of Apple Pay at TUAW today:

Remember that merchants in an Apple Pay transaction never have access to user credit card information and, as a result, users never have to worry about their information being compromised in a security breach. Further, security at the device level is effectively impenetrable as tokens, along with the encrypted keys responsible for the cryptogram, are all securely stored in the Secure Element.

And as an extra security precaution, iPhone owners will have the ability to unlink or temporarily suspend a token connected to a stolen device, thereby rendering Apple Pay inoperable until the device is retrieved.

I may be skeptical about Apple Pay in Europe, but the way it’s been built and will operate is fascinating. (I’m even more curious to know if integration with Safari will happen for web payments eventually).

Kirk McElhearn makes some good points about Apple Pay in Europe:

On its website, Apple touts that fact that Apple Pay will save you time, by not forcing you to search for your wallet and then find the right card. These concerns, too, are specific to the United States. On average, Europeans carry only 1.46 payment cards (more than two thirds of which are debit cards). In the US, people have more than twice as many cards; 14% of Americans had more than ten cards in 2007. Credit cards are much less common in Europe (though adoption rates vary by country), and most people only have payment cards with their banks.

This is exactly why I’ve been struggling to get the excitement around Apple Pay. Sure, it looks cool, but Passbook was also cool and I never actually used it in a real life scenario in Italy. I’ve never owned more than one payment card in my life (the one supplied by my bank) and most people I know don’t have multiple cards. I’ve never understood the videos of modern payment solutions showing people fumbling to find their credit card – I have one, and it’s not that hard to find in my wallet. We still use cash every day for any kind of purchase, at least here in Italy.

I’m sure that Apple Pay will be easy to use and potentially more appealing than Passbook (especially for online payments). I’m just worried that it’s going to be another cool technology primarily meant for the United States.