I have a large hotpad with the pocket on the back, like Tartan mentioned.
I had a jean quilt and some of the squares still had the pockets on them, it was very heavy!
I was given a homemade pie mix in a bag made from the leg of a pair of jeans. The bag my mom got included the pocket, so she added a pretty strap and uses it for one of her knitting projects.
I've seen purses, some using the whole top part of the jeans, front and back, and some just using the pockets. The ones just using the pockets are just the right size for just carrying a wallet and cell phone.
I've also seen a little pouch for carrying your hand quilting tools (thimble, needles, Aunt Becky, tiny scissors), that can be worn around the neck.