The news is coming out fast lately about the various and possible changes in WordPress 1.6. Andy Skelton talks about a new solution for header art in WordPress 1.6 for WordPress Default Themes, also known as the Kubrick Theme. His announcement states that changing the header art for the Default Theme will hopefully soon be done from the Administration Panels. Wow.
Currently, changing the header art in the WordPress Default Theme consists of doing it manually, or using Kubrickr, a utility tool that will automatically switch your header art to any image you have uploaded. It must be approximately the same size and it has a few limitations, but for the most part, it’s fast and easy to use.
There are also hundreds of free header art available for WordPress users from Digital Westex. These are already sized and ready for saving and uploading to your site.
You can learn more about the WordPress header and changing or designing your own in the WordPress Codex article, Designing Headers.