iOS 5 has a great new featured embedded into the OS which will help provide an early alert for earthquakes in Japan. I am sure this technology will be useful in other countries as well, but we are unsure if it will be implement. Hopefully it takes advantage of the GPS radio and alerts you if you are within range of a possible earthquake.
This is some exciting new technology and lets hope Apple and other cell phone manufactures incorporate other warning systems into their phones that will alert the public of possible disasters.
Japan has the world most advanced early earthquake warning system.
When Primary-wave is detected, it alerts ordinary Japanese cell phone and TV to prepare for massive shaking.
Trains, especially Shinkansen (Bullet train) stop immediately.