John Resig has put together some demos for the new CSS 3 border-image implementation that is part of Firefox 3.1. “This is a new CSS 3 module that makes the exact slicing of images (and their positioning around an element) quite easy. The most obvious use case for them exists in constructing beautiful scalable buttons.” You will need a nightly release of Firefox in order for John’s demos to work. He also includes code samples and extensive explanations for the demos.