I recently ordered some PLARN (recycled plastic yarn) from JesSpins. You send her the raw materials -- I sent plastic grocery bags; plastic mesh from clementines, avocados, and onions; an old cassette tape; etc -- and she spins them up. You pay by the yard -- mine worked out to be 99 yards.
I should receive it next week sometime. I'm looking forward to playing with it... and I promise to have Show & Tell once I've got something completed.