Sent to you by David Andrew via Google Reader:
From the website: www.dipity.com "Dipity is a free digital timeline website. Our mission is to organize the web's content by date and time. Users can create, share, embed and collaborate on interactive, visually engaging timelines that integrate video, audio, images, text, links, social media, location and timestamps."
There are a fair number of these coming on stream at the moment, such as Timeglider and my personal favourite Meograph. There is a free version for up to 3 timelines, but then it's £££ after that. Looks easy enough to use, though I confess that I haven't tried this one myself. There are lots of examples of the way that people have used it, which was very interesting.