Found the following article incl. all the bits needed which offers a great solution to text replacement by images using just PHP and aJava script and deflating the actual html. Thus giving ultimate control over the viewing experience of the visitors. I think it's specifically outstanding as it adresses not only the base technique but also the actual viewing experience. http://www.alistapart.com/articles/dynatext/ M
We have done a similiar thing on a few sites using data driven flash files... Gets some nice results...