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: ![alt text][1] and not: ![alt text][2] [1]: /storage/temp/25743-movetoangle.png [2]: /storage/temp/25744-move.png