Eric Meyer has been working on a slide show format that uses XHTML, Javascript, and CSS. The software is called S5: A Simple Standards-Based Slide Show System and it looks like a promising alternative to PowerPoint or other presentation software. S5 presentations require only a recent browser for display. The look and feel is only limited by what you can do with XHTML and CSS (which is to say, it’s not that limited). Check out the introductory slide show for a example of what’s possible.