Giant knit rug with soft cotton rope (can be hand dyed from white/ivory) knit on the most giant needles you've ever seen (the kind with glitter in the plastic tips), by Mary Marie Knits on Etsy, but she no longer makes it. What a fun challenge.
Taking Care Of Your Living Room Rugs : Mushroom Knit Area Rug
Twined rug, with instructions. great way to upcycle jeans and other clothes (cut into strips for "rags" for rugs!