But, somewhat ingeniously, Germany-based Japanese industrial designer Yuya Ishida decided to make a sofa that collapses into a chair out of them. (His waribashi obtained, it seems, in bulk from a local Chinese supermarket.) Pretty impractical, time consuming, and not looking all that comfortable – and of course not a way of disposing of those wasteful used ones – but since part of his expressed aim is to "create products that make people happy" this seems a good place to start.
Personally, I like his solution to seal stamps here in Japan (hanko) which are difficult to press on a solid flat surface (which is where you usually do have to press them). A rocking hanko! I want one. More design thinking on his website.
Spotted via Fastcodesign