I met Hello Knitty on Monday night at Etsy Lab's craft night. Hello Knitty cuts up old plastic bags, spins the plastic like it's yarn, and knits it into new, longer-lasting and stronger bags. I saw a few of these bags up close and I think the spinning is what gives these bags the extra twist.
Now, if that's not a good lookin' plastic bag bag, I don't know what is. This is definitely a great example of upcycling.