timemap
TimeMap is a tool to help show information simultaneously on a map and timeline. Only items in the visible range of the timeline are shown on the map, giving you a sense of both how contemporary they are and how they are related geographically.
TimeMap is currently being used by Ushahidi.com to track incidents of post-election violence in Kenya. I also made a sample page with data pulled from freebase.com, showing artists and authors of the Renaissance.
The TimeMap library is written in Javascript, using the Google Maps API and the SIMILE timeline API. Features include the ability to load multiple datasets and support for KML. I've released TimeMap as Open Source - you can download the code here.