In the big smoke of London they have self-service checkouts. I was in a Tesco the other night in Notting Hill Gate and they have 4 machines beside the door. The kiosk has a card reader built in, you scan your items, pop your card or cash in to pay and off you go with your items.
Apparently at night they have nothing but these kiosks open, which is grand until you need a security tag removed from a bottle of vodka or a DVD.