The Filabot personal filament maker turns ABS or PLA pellets into filament suitable for 3D printing.

Filabot

When the Filabot reclaimer/grinder is ready we’ll be able to recycle used 3D prints to create new filament… and in the future, maybe recycle plastic bottles for filament?  Read more at Wired’s article:  Filabot Turns Your Plastic Junk Into Material for 3D Printers.