Matt Jones at blackbelt jones is collecting examples of timelines from around the internet.
I've been toying with the idea of changing my home page to include a collection of biographical snippets or essays. I'd like to have the page display a single snippet in the center, have a menu to navigate between snippets on the side, and a timeline at the top. I think I could make the timeline at the top dynamically respond to what snippet you were viewing by using javascript to manipulate the background colors of a table. If the project ever gets off the ground I'm sure I'll be mention it here.
Matt Haughey's recently commenced experiment, Ten Years of My Life is another intriguing example of representing time on the internet. I've been dreaming since at least the late 1980s of creating an easy to use timeline for viewing history or any time dependent event. It's mostly been an interesting idea up to this point.