Via E. Shupps:
While following up on a comment from Claudia I found her article on WSS themes. Good stuff - go check it out.
Claudia did a great article on the differences between themes and templates and an overview on how to create each.
The site did prompt me for a login, but I just clicked cancel several times and it loaded the file.
» Working with the User Interface in Windows SharePoint Services: Best Practices for Themes and Site Templates