A friend at work showed me this the other day and I just think it's a perfect example of service design in action. Tesco, a global grocery store chain, has created a way for shoppers to purchase groceries by scanning grocery items on a giant graphic on subway walls using their cell phones and then Tesco will deliver them to the shopper's home.
Amazing service design. Saves time and eliminates a lot of the work of shopping for customers and I imagine it could lead to quite a revenue boost for Tesco. Plus all of the free viral marketing that they are getting.