If you improve your posture you will "walk tall" so even if you are not actually taller you will seem so. Also, stretching exercises will loosen up your spine so you will reach your actual height (i'm 5'3" when I am fully stretched, but I kind of 'shrink' when i'm just hanging around.
Lastly, be sure to drink enough water! The pads between your vertebrae can shrivel up if you become too dehydrate (happened to me in the hospital ~ I was down to 5'1"!)