Chronozoom provides an interactive timeline of the known history of the universe. Maybe think of it as a historical Prezi, where you can zoom in on information, images, and videos explaining what we know. The html5 animation was pretty shaky on my Firefox, but it ran nicely on Safari. The behind the scenes story about the team that created this is a good read.
An addictive collection of beautiful charts, graphs, maps, and interactive data visualization toys -- on topics from around the world.