@Rixyboy pointed me towards this that he had spotted in the Metro. What a cool idea. I don't know if I would be so easily sold on something that I can not touch and get excited about but for quick shops on the way home this would be brilliant. Even better would be if the screens were interactive so that when you came close to the screens they could tailor themselves based on things you had bought before, your lifestyle, things your friends had bought or based on the history of what you had bought, when you would be most likely to need it again. For example it could advertise milk to you based on the sell by date of the previous milk sold to you. AMAZING!