Calling All Crafters: Help With Making a Wrist Wallet

Hey fellow crafters--

I am having trouble figuring out how to make a wrist wallet. Have any of you seen patterns out there for an item like this:

It has a hidden zippered pocket for small items and cash and fits over the hand and on the wrist without snaps, buttons, or any other type of closure. In other words it's one continuous loop around the wrist. My step-mom Laurie saw them in a magazine and was hoping I could make some but I just can't figure it out! Help!