I've noticed a ton of wood and bamboo products popping up lately and just spotted these Handcrafted Wood Shells for the iPhone ($40) available in bamboo, walnut, or cherry from Vers (which has a history of creating stylish and chic wooden electronics).

The impact-resistant cases have connector and camera openings, allowing full use of your phone while in the case. Plus, for every tree used in production, the manufacturer replants 100 trees in conjunction with the Arbor Day Foundation and US Forestry Service.