Today I was down in Sheung Wan, the dried seafood area of Hong Kong, to shoot a small feature on crocodile meat. On the way there I passed by a small shop on Wing Lok Street which had a sign in it's window advertising to buy gallstones, (a friend had wrongly tipped me off that they were out to buy gall bladders!). Apparently they are only after cow, not human gall stones, as I was assured by the friendly shop owner with a smile on his face and his arm draped around my shoulder. It seems that cow gall stones are the size of a golf ball and yellow in colour, but he didn't have any to show me as they were "all packed away". According to him, crushed and powdered cow gall stones are used in Chinese medicine to improve liver function.