eQuake alert is a handy add-on, which alerts you with the basic information (date, location, and magnitude) of each earthquake. By default your browser will shake proportional to the earthquake magnitude. You can configure the alert methods and even you can limit the alerts by the earth quake magnitude. The recent quakes menu provides a link to the detailed information of quake at the USGS (US Geological Survey) website.
||Firefox 1.0 - 3.5