Grove, a company based in Portland, Oregon, specializes in using sustainable, eco-friendly materials. Their new case for iPhone 4 only adds .07 of an inch to the thickness of the phone, with a metal bezel and custom engravings on the back.
Normally priced at $99, they're currently selling them off for $49 if you pre-order. That $49 price is for the plain variety, but if you'd like an engraved one, then it'll set you back $69.