The simile team has published another nice reusable component: timeline visualization.
In their words:
Timeline is a DHTML-based AJAXy widget for visualizing time-based events. It is like Google Maps for time-based information.
A introduction howto program it is here:
A first glance at it convinces me: this looks easy to use. They published the code in a SVN repository, so packaging it with something else is possible.
Danny Ayers pickes up the idea, and blogged a nice vision of how to combine GEO-data together with photo annotation and timelines, read here.