I've been playing around this morning - cutting up an old t-shirt and winding it into a ball of yarn. I found this very enticing tutorial via Pinterest and had to give it a go.
My yarn didn't end up looking quite so smooth and due to probably a slightly blunt pair of scissors I now have very sore hands - but thought I'd round up the morning trying out (another!) a bangle:
Three rounds of single crochet was all that was required to make this very sturdy and rigid bangle - it looks slightly 'rustic' around the edges, but overall I am pleased with the result - I think I just need to work on making a better ball of yarn in the first place -better go and sharpen those scissors!