One of the problems I’ve encountered many times is when photographing a painting or a poster or anything flat on the wall or placed on the floor: unless the camera is absolutely parallel with the flat surface in both the horizontal and vertical planes, the object looks distorted in the resulting photo. I’m not sure if it’s already been done, but a facility that made sure that such photos came out correctly would be a really useful feature on a camera (among the many others that I know I’m not aware of!).