speed edit straighten

Why the hell there is no straighten key for aligning a photo? I wish where was a key which shows up a grid line (which should be custumizeable in thickness and transparenzy) and cursor up/down and/or mouse scrollwheel rotates the photo in 0.1 degree steps. I that really so difficult to implement? It would speed up my work so much. It would be much faster than using a straighten line, because point and click exactly take to much time.