检索加速度计值？

UIAccelerometer *accelerometer = [UIAccelerometer sharedAccelerometer];
accelerometer.updateInterval = 1.0f/60.0f;
accelerometer.delegate = self;

-(void)accelerometer:(UIAccelerometer *)acelerometer didAccelerate:(UIAcceleration*)acceleration 
{
    // here you can use acceleration.x, acceleration.y, acceleration.z 
}