Some "Cold Storage" branded supermarkets have this new high tech shopping carts in their stores. I have yet to hold one of it (I just took a photo of this poster), but it reminded me of an assignment for one of the modules of my Masters course I took around 6 years ago.
My group mates and I came out with a business proposal and our topic was about these shopping carts! Our Professor did not really think it was a feasible idea and thought no one will implement it. But look, someone did! ( I think I still have the assignment and his remarks!)
Not sure what the function of this cart has, but our proposal had sensors on both carts and around the store that can keep track of user behaviour and show relevant promotion as they go through the aisles. There were many other things too, but I can't remember the details.
If you want to see how the cart looks like, look at ZS's blog post here. You can click on the photo of his daughter on the cart to expand it. ;-)