Crafting a loco!

Using a crafting table with Button, 'Blank', Lever then Wool, Wool, Wool, then Minecart, Iron, Minecart (or similar arrangement of suitable items), you could craft a loco that has directional control with the lever and power  control using the button (toggles on/off).

This loco could stick to minecarts and cause other minecarts that come into contact with minecarts in the train to also stick to them thereby creating a controllable train of minecarts for moving your items or friends!