Life Haps is the latest online tool to create timelines. It’s primarily designed for people to create timelines of their own lives, but could be used by students to make ones for historical figures. It does allow you to grab images of the web easily, which is a nice feature.
There are now so many timeline web applications out there that I guess it’s time for me to make a “The Best…” list about them, so that will be coming-up. In the meantime, you can see links to many similar tools on my website under Student Timelines.