Simple, plain text, with no fonts, colors, CSS, animations, or any of that stuff. Aimed at the ultimate in compatibility with minimum of features. Should work on just about anything, even small-screened phones.

Fancier, with fonts, colors, and nifty CSS styling. Should work on more modern smartphones and PDAs, with more current browsers.

Even cooler, with javascript-based animations and magical navigation bar. Designed for the iPhone / Mobile Safari, should work pretty well on other WebKit-based browsers and even things like Firefox or Opera. Not guaranteed to work on all high-end phones, but worth a try. Uses advanced HTML 5 caching fu to provide offline support.