When I first discovered these cool little things, I wanted hundreds of them. Not just for my book covers. These are a great way to show support for your favorite author or series. You can probably even get your favorite shows on them. At Etsy--which is where I got my charms--you can ask for a custom order. Pretty much anything you want on them is possible. You can get them on bracelets, necklaces, or keychains.
Here is my bracelet:
They have sample pictures of bracelets ordered by customers. The most popular one seems to be Harry Potter. It is a cool idea, and I love these little charms.