Traditional warning systems use dedicated sensors, networks and central computers to generate their estimates of seismic impact and alerts. But in the same way that smartphones have changed our lives since being introduced just ten years ago, researchers in the US, Mexico, Chile, Japan and elsewhere are looking to use a distributed network of personal smartphones connected over cellular networks to create a ‘crowdsourced’ EEWS. Today’s smartphones have high-power computer processors, GPS chips and accelerometers, plus radios to connect with cell networks — in essence, everything you need to do seismic detection. Researchers are testing to see if these devices, especially their built-in accelerometers, are accurate enough to support a warning function. And they are. In Chile, a team of local and US researchers is developing and deploying an early warning system using only smartphones and an inexpensive add-on for greater accuracy. Data collected by the sensor boxes is transmitted through an Android app developed by the researchers and analyzed to produce earthquake source models, which in turn can be used to create ground shaking forecasts and local tsunami warnings. A team at UC Berkeley has also developed an Android app with similar functionality which anyone can download and use as a seismometer. Someday these distributed personal networks may even be linked with the centralized systems to provide enhanced warning data and alerts.