Get the shopping in...
Two awesome ways to shop:
1) Shopping cart with tablets built in that work with an app you download to your phone. Lots of real time shopping frolics commence!
2) Photographs of items on subway walls that you can scan with your phone, and have Tesco deliver to your door once you get in. Notice how most of the items are duplicated - they don't have to be, but then it wouldn't look like a supermarket shelf and might put commuters off using it. Hopefully I'm right and now I look really clever.