iPhoneInput.acceleration, rotation within limits?

I'm trying to rotate an object using the iphone accelerometer (which is easy enough), but I'd like to limit the rotation to something like 30 degrees (+-) on the X axis, for example.

Also, how would you define a dead zone so the user can easily find the zero rotation again?

This might be used for limiting how far you can turn a car's steering wheel or the pitch of an airplane so that you can turn or dive without accidentally over rotating.

Can anyone provide an example using either transform.Rotate or rigidbody.AddTorque?

just a guess

if(Input.acceleration.x > 30.0)

Input.acceleration.x = 30.0;