I think just go to a key shop/locksmith, NOT Walmart, Home Depot etc. i also think someone said it is a Gas Cap Type Blank. Somebody else will offer more ideas. Also----Consider going to "Tools" in the red banner, click on "User CP" go to "Your Profile" then click "Edit Your Details". Then, whenever you "post" something, it will show in the left column under your name, like the rest of us, and we will know where you are and what you drive. Then if you have a problem, someone close by might be able to help out.
Nick