the latest offering from russian studio art lebedev (previously mentioned here and here) is flashkus, a disposable cardboard usb drive. these usb's come in sets of four, divided by perforations which make them easy to separate and use. the material allows for the user to write directly onto the drive, to indicate what it stores. perhaps not so good if you change what is stored, but still a nice idea.
the one thing that gets me though, is that these are 'disposable', which isn't actually any different from any other usb out there. if it was recyclable, now that would be new, but surely anything is disposable?