Plastic Bottle Cutter
It’s not high tech by any means, but the Plastic Bottle Cutter does one thing and does it well: transform your recycling-bound plastic bottles into highly durable plastic string. This compact wood and metal contraption uses common small cutter blades to slice bottles into different widths of rope, adjustable using the thumb screw knob on its side: all you need to do is cut off the bottom of the bottle first, iron out patterns and wrinkles in the bottle (if need be) over a light heat source, then insert it into the device and pull. The resulting rope itself is surprisingly strong — if not a little sharp — and suitable for various DIY uses.
Find it at Kickstarter – roughly $22