CSS, Background Images, and Rollovers
It occurred to me that this ought to be possible by reassigning a container's background-image property when it is :hover-ed.
Yup, and you can do the same for every other pseudo-class of an anchor tag. I read about this via Eric Meyer’s article on the O‘Reilly Network. I’m still very much a CSS neophyte, but it’s helped me incredibly at work, where I was able to create a site layout with one set of HTML pages styled by a small library of CSS files for look & feel.