Hurry up! I want to save the world right now, dammit.

Solution

Three easy steps to the front of the line and out the door:

  1. Skip the line-up at the counter.
  2. Give your reusable cup/mug to baristas who make your desired beverage and hand it back.
  3. Leave and enjoy. (Remember NOT to pay)
The core motivation is that people on the go want to keep moving (also more likely to turn to disposables) - most people get the same coffee all the time and most people are on the run when they do so. 
The core functional element is an embedded RFID tag. Your desired beverage can be set and changed by any device with wi-fi or potentially in-store at a kiosk.
Your choice of cashless payment methods is logged at a secure website or via the  myStarbucks app. This allows you to run a tab or pay as you go with instant withdrawals from your e-cash provider.
No line ups, no fumbling for cash or other payment methods in the shop.

Oh, and you just did something good for the world.
Starbucks Express