Not many people know about it, but several major version numbers ago, Opera introduced a feature called Opera Show. This feature allowed you to invoke a projection-medium display mode by hitting a single key. (They’ve since introduced a similar single-key invocation of a handheld device.) In this mode, any style sheets that applied to the projection medium were used to present the document. It was a lightweight form of Powerpointâ€”not as powerful, perhaps, since it was best suited to showing a slide show of static pages, but definitely useful. Many of my talks over the last two years have used Opera Show.
The great thing is that with one (X)HTML document, you can have a slide show, a printer-friendly version, and a screen presentation. I put markup and CSS examples right there in the document, ready to be printed, and simply hide them in the slide show. In some cases, I printed out the file for handouts, and then used the exact same file for the slide show. It was very, very handy.
Eric and a few other folks have tweaked the concept so that it’s not an Opera-only feature. In fact, Eric’s version works in every modern browser. You can try it out, or download a zip with everything you need to start making your own. Very nice.