Ivan take a look at SMIL Timesheets:

It may seem like a odd concept but if you make a few examples and see how it works, it's a great design.

There is a partial implementation of it in javascript:

The question of when will see SMIL in HTML. My guess is, first there needs be native audio/video support. Which makes vorbis/theora crucial. After that SMIL Timesheets need to become a Recommendation then the multimedia fun
begin :)


-------- Original Message --------
Subject: Synchronized Multimedia and HTML5
From: Ivan Moura Campos <imcampos@ufmg.br>
Date: Mon, July 06, 2009 11:47 am
To: public-html-comments@w3.org

Hello there,
I cannot find any functionalities related to time and synchronization (all present in SMIL) in HTML5. Will it stay that way? Already Firefox and Chrome support HTML5, none supports SMIL. Is SMIL toast?
Ivan M Campos