Using the accelerometer

With iOS version 4.2 and newer it is now possible to read accelerometer and gyroscope data via javascript. Here’s an example, what could be done with it: http://isthisanearthquake.com/

To read the data from the accelerometer use the following javascript event:

window.ondevicemotion = function(event) {
// event.accelerationIncludingGravity.x
// event.accelerationIncludingGravity.y
// event.accelerationIncludingGravity.z
}

If you want to read the data from the gyroscope (iPhone 4, iPod Touch 4G+ and iPad 2 only):

window.ondeviceorientation = function(event) {
// event.alpha
// event.beta
// event.gamma
}

For more information visit: http://www.mobilexweb.com/blog/safari-ios-accelerometer-websockets-html5

Shake Event

If you need to create a shake event (for example to fetch some data when shaking the device) take a look at http://www.jeffreyharrell.com/blog/2010/11/creating-a-shake-event-in-mobile-safari/