Bamboo Computer Mouse & KeyboardIf you want to be "natural" this is an option for you.
From Japan comes this optical bamboo mouse. It's made with polished strips of bamboo. Bamboo is a readily renewable resource, and it's one of the hardest woods in existence. The Evergreen company makes the mouse, along with a matching keyboard. The mouse goes for 3,980 Yen ($34), and they keyboard is available for 7,980 Yen ($68) from Donya.