Hello... I'm so excited to share my idea with all of you! 
Many retailers already sell branded, reusable, steel travel mugs that can be refilled at any of their stores.  I'd like to take this idea a step further and create a program where either a  Universal "code green" mug or any personal mug can be used at any participating coffee retailer, whether it is Starbucks or any other coffee house.  

The idea is to use a keychain tag that contains a unique serial number will be provided.  Once a person has a serial number, they can activate their account on the program's website allowing them to measure the positive impact they are having at reducing paper waste.
An application can be written to link the program website to the user's Facebook account (or other social media websites), further promoting the program's success. (e.g. Jane Doe saved another paper cup from reaching a landfill today!) 
When a person purchases a refill using their Code Green mug at a participating coffee house or retailer, the retailer will scan the keychain tag which will track the individual's contribution to the global effort to reduce paper cup waste. 
Add up all of the program participants to calculate the global success of the program!
I should add...( for I've already had responses on facebook) that...the program is the idea... not just the reusable mug. (Though purchasing the "code green" mug is obviously a great method of advertisement for the program. ) Any reusable beverage container may be used to participate in this program. The membership # is the key to tracking one's success with helping reduce paper waste. Follow it up with a social media application to further promote the program by telling your friends that you have helped the environment! An option to note the location of purchase , may be added as an option. Invite your friends to join you! The public have proven that they love applications , games and telling friends good news! Let's use this knowledge and generate a positive vibe and watch it grow! How about a virtual tree that grows as the consumer participates in the program! It's a fast spreading promotional idea executed in an environmentally friendly manner.  
To make it more appealing to retailers or coffee houses, this program also allows the participating retailers to hold individual  " Code Green" promotional deals or discounts if they so choose. They are not being forced to follow the same incentives. This allows there to be a  certain amount of competitiveness between the retail participants... eventhough we all have one common goal.

Why not bar code the mug?
In order for this to be a successful program. We can't solely rely on the use of one mug. The key chain tag allows the consumer to still use the program in the event that they would forget, damage or lose their mug. Maybe they forgot to clean out their mug and they are without a container today. How frustrating would it be if the bar code was not able to be scanned because they dropped it on the ground or over use has made it illegible?  The use of the key tag allows the consumer to use a refillable mug of their choice, or use an "in house" mug at a participating retailer and still get credit for their contribution to the program. Our goal is to not frustrate or punish a program member for not having a specific beverage container. This keeps the cost of beverage container replacement down and makes the program work easier for everyone.