The potential for using a mobile device to shop in general is most exciting. Think about this: you are walking by a poster advertisement for your favorite band. You use your cell phone to scan a bar code that allows you to download a free track. All this while you wait for the bus. I believe in the future, all print advertisements will have these codes. It is already happening, i just think it is really cool, and the potential for gorilla marketing is high. just my two cents.