Tiny Cartridge just posted on this great brochure picture of a Nintendo Knitting Machine designed for the NES. Apparently, the machine was only shown once at a trade show in the US. Lack of potential buyers at the show doomed it and the whereabouts of the device are unknown today if it still exists.
I can't even think of the potential and modifications that people could be doing with it today if it was ever released. Maybe Wii Generation sewing machines would exist and Nintnedo would be afraid to make their next system have a 3D printer be a part of it. Just think of a Nintendo 3D Printer
If you follow the source of info Howard you can also see the never realized wireless Nintendo Advance. It apparenly didn't work that well.