Meet the wi-GO: an autonomous self-driven shopping cart for folks with reduced mobility. It has a 3D camera that allows the device to identify one person at a time and avoid obstacles. It does not require any physical effort by the owner to use the wi-GO.
Think about the possibilities here. A solution like this can be used in supermarkets, hospitals, and even the corporate world (with some adjustments). You can support the wi-GO project on Indiegogo.