This could be a good one. Mirel P1003 is the injection molding grade of a polyhydroxyalkanoate (PHA) based resin developed by Metabolix. The resin is sugar based and is degradable in natural soil and water environments and both home and commercial compost.
Mirel has good heat and moisture resistance. It has good UV resistance without additives, can be colored and has good mold surface replication (both high and low gloss.) It is being evaluated for living hinge applications and early results "look promising". Processing times are similar to those of petro-plastics. Best of all, the resin is available NOW. The manufacturer is claiming replacement of ABS and polycarbonate as well. Here's the spec sheet. Mirel is also available in film and extrusion grades.