throw objects based on mousemovement

Hi,

I want to throw an object into the distance when left button is released based on mousemovement (Like in Black and White: http://www.youtube.com/watch?feature=player_detailpage&v=sVSu-U1osQo#t=1009s).

I made a script (posted below) which lets you pick up the object it is attached to and throw it forward. However it is based on the mouseposition the moment you let go, I'd rather have it go further based on how fast you moved the mouse. I have no idea how to start, so if someone could point me into the right direction, that would be great!

the script:

 bool move = false;
     
     // Update is called once per frame
     void Update () 
     {
         Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
         RaycastHit hit;
         if(Physics.Raycast(ray, out hit, 500))
         {
             if(hit.collider.gameObject == gameObject && Input.GetMouseButton(0))
                 move = true;
     
             if(move)
             {
                 Vector3 goTo = new Vector3(hit.point.x, 2, hit.point.z);
                 gameObject.transform.position = Vector3.Lerp(transform.position, goTo, Time.deltaTime * 100);
             }
         }
         else
         {
             move = false;
         }
     }
     
     void OnMouseUp()
     {
         move = false;
         rigidbody.AddForce(Camera.main.transform.right * Input.GetAxis("Mouse X") * 15f, ForceMode.Impulse);
         rigidbody.AddForce(Camera.main.transform.up * Input.GetAxis("Mouse Y") * 20f, ForceMode.Impulse);
     }
 }

EDIT: It would seem that delta mouse position is received by Input.getAxis("Mouse X/Y"). I confused it with horizontal/verical. So I'm guessing the distance already depends on how hard you move the mouse? I'm not really happy with the result..