I give many of my talks using a very basic HTML template that creates the illusion of slides. It has a few advantages
- it’s free
 - it works on any browser and any OS
 - my talks take up very little space, file-size-wise
 - I’m not using someone else’s proprietary software or the same old clip art you’ve seen a million times before
 - talks are available in the same format online and off
 - easy print option with extra space for hidden notes [new!]
 
There are a few downsides as well
- it’s not totally standards compliant. If you need total compliance, use S5, it’s great.
 - you do need to know a little HTML to make it work for you
 - Since you’re not using PowerPoint, you may tend towards wordiness.
 
People have been asking about it, so I’ve decided to make a blank presentation with all the stylesheets and whatnot, available for downloading. It’s just a basic HTML page, two stylesheets, a sample image or two, and a styleswitcher. Try it out, tweak it, let me know what you think.