As I tried on my colleague's Google Glass headset, I had a flashback to my first time using the Starbucks app to make a payment. And I was surprised to find Google Glass worked better.

The Google Glass headset is a slim but conspicuous mobile device that puts a camera and screen in front of the user's right eye at all times. Since it's still not available to the wider public, Google Glass doesn't have a rich selection of apps to choose from, so I wasn't able to test it with an actual mobile wallet. But I was able to see how well Google Glass reads QR codes, a technology at the heart many mobile payment systems in use today, including the Starbucks Card and LevelUp.

When I tried it out, I expected the experience to be like my first time using the Starbucks app in 2010, when the mobile payment system worked at just 1,000 Starbucks stores. At the time, the barista and I couldn't get the app's bar code to line up with his scanner, so he wound up typing in my card number.

Today, Starbucks seems to have worked out all the bugs. The last time I used the app, it was so effortless that I don't think the barista even looked at my phone. Starbucks gets 10% of its U.S. sales through its mobile app, or 4.5 million mobile payments a week.

So how does Google Glass measure up? When I sat down at my colleague's computer to read the QR code that would connect the Glass headset to a wireless network, it worked so quickly that I didn't even realize it happened. I tried it a few more times with the same result.

Standing up from the computer, I was too far away, but the built-in display showed me the camera's perspective and made it easy to see how to line things up. I got it in seconds.

Would this work in a payments setting? I'm not convinced of that yet. It worked when I was at a comfortable distance from a computer screen, but I don't know if it would be so easy to read a QR code off a terminal at the point of sale.

Terminal screens are usually at waist-level to make them easier to sign with a stylus. To read a QR code off such a low screen, I'd have to lean over like a bird feeding its young.

That said, the headset's built-in display provides instant feedback, addressing a concern I have with mobile payment systems today.

When I make a smartphone payment at the point of sale with LevelUp, for example, the reader changes color, but my phone's screen is still facing away from me. I have to have confidence that the payment went through before I pull my phone away to view the confirmation or receipt. With Google Glass, I'm already looking at the right screen.

And although QR codes are a natural choice for a mobile wallet, they are not the only choice. Square and PayPal let users "check in" by detecting their location, and Google Glass could easily do the same thing. Shopkick and the upcoming Crinkle use sound waves to detect a user's location, and Google Glass' built-in microphone could work with that sort of system as well.

Since the whole point of Google's phased rollout of Google Glass is to whet developers' appetites, there are probably many more payment methods possible than we're discussing today. A few banks are experimenting with augmented reality, a technology that should flourish on Google Glass. But for what it can do even at this early stage, Google Glass has crystal-clear potential.