Here's a video showcasing the potential of Google Glass.
All I could see in this video is Google Glass' potential for frustration. My experience in paying for a coffee would most likely go something like this:
Me: [me paying for coffee, speaking to glass] Ok glass, pay for coffee, use my credit card
*Glass: Using debit card ending in 4516
**Me: No glass, I said *credit card
Glass: Which credit card would you like to use?
Me: My American Express
Glass: Which American Express would you like to use?
Me: My gold card
Glass: Error. Sorry, you don't have a "gold" American Express card. Valid types are cards ending in: 4512 and 7483
Me: I don't know, use the card ending in 4512
Glass: Processing … transaction cancelled. Trying again … it appears you don't have any money on this card. Trying American Express card ending in 7483 … processing
Me: [speaking to cashier] Sorry, it will just take another second, my card isn't going through. I always have trouble with that card. American Express always stops transactions on it, I wonder if it's beca...
Glass: Stopping transaction...
Me: No Glass! I wasn't talking to you. Keep using that card.
Glass: Transaction stopped. What would you like to do now?
Me: Ok Glass, let's try this again. Pay for coffee.
Glass: You don't have any valid credit cards, but you can add a new one. What's the number?
Me: I don't' want to say my credit card number out loud.
Glass: Error. What do you want to do now?
Me: Damnit glass. Ok pay for coffee. Use PayPal
Glass: Password please?
Me: Damnit I can't say my password here in front of everyone! Glass: Password please?
Me: Ugh, damn you glass.
Me: [speaking to cashier] I'm sorry, I'm going to have to just not get this coffee
Me: [walking out the door, speaking to glass] How much does a used Google Glass go for on eBay?
Glass: Searching Google for used glass gophers on eBay