Love the Earth? Love plastic bags? Why not melt them together and add an old t-shirt for the lining in order to create a laptop case? Using an iron and a bunch of crinkly bags you can create sheets of plastic that you can then sew together to create a bag, jacket, or pants, thereby save the Earth and showing the world how much you like bags in one fell swoop.
The Instructable is fairly straightforward but it does require some sewing skill.