From Two Pilots:
Rotation Pilot is a set of handy tools for rotating, resizing, and flipping your photos. To adjust a visual slope of a photo you should only set a vertical or horizontal axle and the software will do the rest. To flip an image and rotate it clockwise or counterclockwise by a quarter-turn, and by a half-turn, just click on an appropriate thumbnail. An arbitrary rotation angle can be specified in the entry field (3). Positive numbers correspond to clockwise rotation. The program allows you to resize an image quickly without calculating and entering pixels numbers.