RE: X.O. sauce.
Grace Young's recent book, The Breath of A Wok, has a very good description of XO Sauce and how to make it. It's origin is from Hong Kong. I can buy it at asian markets where I live, but not the Yank Sing version. My daughter found it in Minneapolis. I don't really believe that it is made for the western market, but it's ok with me if it is. It's very enjoyable on noodles and seafood.