Further to massive public demand (well, one request!) I will dedicate this post to instructions on how to cut up a plastic bag into strips suitable for knitting.
These instructions are my take on those given in Simply Knitting (October issue I think) .
First take a plastic bag:
Cut off the handles (top part) and the bottom (seamed part)
You will now have a big plastic tube.
Now fold the plastic tube up so that there is about 2cms showing at the top.
Cut into the rolled up part of the bag so that there are strips of about 2cm wide. Do not cut up to the top of the bag (if you do, it isn't the end of the world but you will have short strips and you will have to tie the strips together).
You should then have a piece of plastic with plastic strips hanging down.
Cut into the top part of the strip diagonally to the left so that you get a continual strip (like orange peel).
If you cut too enthusiastically or too straight and get shorter strips, don't worry, you can tie them together.
Then roll the strip into a ball and repeat with more carrier bags, knotting the strips together as you go.