Discusses various uses of rotation matrices. The author has used rotation matrices to find the patterns with elements in a conformal array that requires one to rotate not only the direction, but the polarization directions, as well. A second useful thing to do with rotation matrices is to analytically rotate objects in space. In computer graphics, it may be neccessary to rotate the object. Many computer graphics texts have useful discussions of object rotations using rotation matrices. A third related use of rotation matrices is to understand antenna positioners. One can describe the rotations of a positioner by rotation matrices, and calculate the effects of rotation not only on the directing of the antenna, but on the polarization directions, as well.