Check these guys out. http://www.newsungear.com/home.html. Its not the easiest site to navigate, you have to look at both the Products Section and the Online Store, but they have some interesting stuff. Under Waist Packs in the Products Section there is a thing called the D.I.Y. It's a pocket that slides onto a belt. I can't vouch for their quality, but I was going to take a chance on them.
Biscuits