I've just come accross these fab bangles made from old plastic knitting needles by Liana Kabel
It's dead easy to do at home, all you need is a pan of boiling water, plastic knitting needles, a bangle mandrel/ former (or rolling pin... or anything round to wrap the needles around!)and a well ventolated area!
Just heat up the knitting needles in the boiling water, then after 5- 10 minutes take them out (using tongs) and wrap them around your former.
I wore thermal gloves when handling the hot plastic but it cools down quickly so you need to be quite quick. Once it's in the right shape hold it into a bowl of cold water to set. If it isn't flexible enough just put it back into the water for a bit longer and try again! Easy!
Apparently you can use a steamer, but it didnt seem to work as well as the boiling water. Happy bangle making! x:-)
If you don't fancy making them you can buy them from Liana Kitch on Etsy, she has all kinds of wonderful kitch and recycled jewellery!