Step 14: Put everything in the box
The box I used already had a window in it so I didn't have to make one. If your box don't have a window, drill four holes where you want the corners of your windows and the use a small saw, and saw between the holes. Then sand the edges.
Drill a hole in the backside of the box for the power cord. To be able to make the hole small, cut off the cord near the wallwart, where it won't be noticed, put it through the hole and then tape it togheter again with electrical tape.
If you like me didn't use header pins to connect all your wires I highly recommend you to secure all wires to the arduino with tape before you try to put the arduino into the box.
If you have an diecemilla or older arduino, remeber to change the power jumper to external power.