Soda Bottle "Pre-Forms"

Even at my age, I often come across stuff that intrigues me. I recently acquired some soda bottle "blanks" or "pre-forms". They are basically a 2 litre pop bottle just before it is expanded and shaped. They are just over 5 inches long, and only hold an ounce or so, but they are very thick, and strong. They contain the same amount of plastic as a 2 litre bottle. With a standard screw-on cap, they make great containers for misc "stuff"...