Here is a hand made dog collar I built for Georgia. The design is taken from the traditional Anasazi culture. See the video below for a short look at the construction process.
This is a cannon that my brother and I made from an oxygen cylinder. With 0.25 - 0.5 lbs of black powder it can shoot a cannon ball anywhere from 300 to 1,200 yards depending on the tightness of the bowling balls fit in the barrel of the cannon. We shoot it off every Christmas.