1

I am using this:

dir.z = Input.acceleration.y;

to translate the y angle of my iphone into z transform of a game object. At present my phone must be held in the wide screen orientation to achieve a null.

Question: How could achieve the same result from a portrait (vertical) orientation?

Here’s the whole code sample below.
// Move object using accelerometer
var speed = 10.0;
var mag:float = 2;

function Update () 
{
var dir : Vector3 = Vector3.zero;

// we assume that device is held parallel to the ground
// and Home button is in the right hand

// remap device acceleration axis to game coordinates:
// 1) XY plane of the device is mapped onto XZ plane
// 2) rotated 90 degrees around Y axis
//dir.x = -Input.acceleration.y;
dir.z = Input.acceleration.y;

// clamp acceleration vector to unit sphere
if (dir.sqrMagnitude > mag )
dir.Normalize();

// Make it move 10 meters per second instead of 10 meters per frame...
dir *= Time.deltaTime;

// Move object
transform.Translate (dir * speed);
}
2

I hacked the dir with this:
dir.z = -(Mathf.Abs(Input.acceleration.y - 1));
This results in all rotations on the y axis translated as positive motion. It works for now. Feel free to post other suggestions.