This is what I'm doing:

Update () {

    if (Input.touchCount > 0) {
         tempDirection = Input.touches[0].deltaPosition.x;
    }

    directionVector.x += tempDirection;
    if (directionVector.x <= -maxMove)
       directionVector.x = -maxMove;
    else if (directionVector.x >= maxMove)
       directionVector.x = maxMove;

    if (fakeShip.position.x <= -maxMove)
       fakeShip.position.x = -maxMove;
    else if (fakeShip.position.x >= maxMove)
       fakeShip.position.x = maxMove;

    fakeShip.position = directionVector;

    if (fakeShip.position.x >= -maxMove && fakeShip.position.x <= maxMove)  {
       myTransform.position = directionVector;
    }

}

So basically you can move object with touching and moving your finger left and right. (typical arkanoid game)

This works nicely on most android phones (tested with ZTE Blade, Samsung Galaxy Nexus (4.0ICS) ...) But there is serious delay when you are trying to play this on Samsung Galaxy S2 (4.0 ICS) tried at least with 3 different S2 phone and it has same delay. (This phone is the most popular, so I need to get this fixed)

Any advices?