Find this case on etsy: http://www.etsy.com/listing/89804208/simple-iphone-4-leather-case
I made this case from (roughly) 1.3mm thick vegetable tanned leather. Hand cut, dyed, stamped and finished, it is a simple case to protect your iPhone from scratches when you throw it in your bag.
I dyed the inside black to make sure that you can’t see dirt on it too easily after a few months/years of use.
The outside colour is a mix of yellow and whiskey and dyed by hand as well. I gave the leather a distressed look and feel and it will nicely age if you take good care of it by occasionally oiling it and keeping it relatively clean.