My mom drinks everything out of single serving plastic bottles and doesn't recycle. It drives me nuts, so I've taken to saving them all but my closet is only so big! I had to find something to do with them.
I used the plastic to create a solid curved base for cable knit bracelets. I love that I can use my scrap yarn and recycle bottles into one giant recycling/destashing project. This would be really easy to customize as well. I've got the free tutorial up on my website (below) and on Ravelry, but I've been wearing my prototypes nonstop. I love big cuff bracelets, but I hate the noise of bangles and don't like anything cold on my skin when it's cool outside. Bingo.