this is a box that uses a unique form of motion to move without wheels or treads. it is simple and inexpensive to build.

parts list:
any durable box
metal rail and slider
a flat metal can with a lid
a steel ball
a small flap of plastic
any type of DC motor
around 10" of wire
small socket and plug (earphone jacks are good)
a battery holder
a toy car to put the battery holder on (optional)

Step 1: The Frame

First, screw the rail into the box at about a 30 degree angle. Screw the lowest screw slightly more loosely so the slider won't slide out of the rail. Also insert the socket by drilling or cutting a hole in the side. Insert short wires into the socket before it is mounted onto the box.

Step 2: The Movement

Take the flat metal can and glue the plastic flap on the inside so one end is connected to the edge and the other end is in the center of the can. Put the steel ball in and glue the lid shut. Attach short lenghts of wire to the terminals of the motor and attach the motor to the lid of the can.

Step 3: Putting It All Together

Take the movement mechanism and attach (preferably with hot glue)the motor to the slider and splice the motor wires and the socket wires together. make sure the movement mechanism can slide freely on the rail.

Step 4: Finishing Touches

Add wires to the plug and connect the wires to the battery holder. Optionally, you can connect the battery holder to a toy car so it won't be dragged along the ground. To use the walking box just plug in the batteries and watch it go. Make sure the wires attached to the plug are put in the right way or it won't go anywhere.