I have always felt the magnetic force of liberated, mobile and adaptable content. The SIMILE projects from MIT are great examples of this concept. In preparation for writing several novels, I have been assembling chronological data on the ancients. In order to visualize this data, I considered creating timelines in HTML, manually. Then I found SIMILE Timeline. When I first saw it, I let out a literal whoop!
Timeline is even better than I had hoped. The data is separate from the presentation, the presentation is layered and modular, and the code is concise and elegant (what I've seen of it). To top it off, everything runs in the browser (very AJAX-like), so there is minimal supporting technology required!
Now I have just begun to create these timelines out of my notes, so take a look at some of the examples provided by SIMILE until I have mine ready for beta testing.