Add Force to the right of the rigidbody, not right of the screen

Using addforce to a rigidbody with vector3.right causes it to move right, even if it is rotated. My question is, how can you get the rigidbody to move from its angle. For example:

and not:


Use AddRelativeForce rather than AddForce. AddForce uses the global coordinate system, AddRelativeForce is local to the target object.

var force : Vector3;