eQuake Alert is a free Firefox addon which delivers earthquake alerts direct to your browser. The really clever thing is it shakes your browser screen as it happens, varying in intensity depending on the severity of the quake.
I’ve had it installed for a couple of days and it’s pretty unnerving to realise how many quakes there are every day and how severe some of them can be. As I’m looking at the status bar now, I can see a 3.3 in Southern Cal has just passed. A good way to remind yourself how lucky you are to be sitting in the safe zone.
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.