All made from two Altoids tins.
Step 1: Parts.
-Arduino board. (Mine was an Uno)
-2 Altoids tins.
- A small breadboard.
-Jumper wires. (For the breadboard)
-A small switch.
-A few LEDs.
-A servo. (Try to lean on the smaller side)
-A small baggy that fits your Arduino board.
-A small phillips head screwdriver.
-A simple 1.5 volt motor.
-An Arduino USB B cable.
-A jumbo paperclip.
-Hot Glue Gun.
Step 2: The Skeleton.
Take one of your Altoids tins and hot glue the breadboard to the top. If yours has adhesive backing then you won't have to.
Glue the bottoms of your two tins together, making sure that the hinges are on opposite sides of each other.
On to packing!
Step 3: Packing.
Slide it in it's baggie and put it in the tin with the breadboard on top.
I put the screwdriver on top of the board to help prevent rattling.
Now start on the bottom tin. Put the servo in first, wires second and extraneous items like LEDs, in last.
Once you have everything in, go invent something on the fly!