"Track To Normal" Constraint

I think Blender needs to have a "Track To Normal" constraint -- that when the owner is constrained to an object, always rotates itself (with regard to an offset angle) to align with the normal of the nearest face of the object it is constrained to. More like "Follow Curve" in Follow Path constraint.

Possible application: automatic control of the base angle of the feet (the angle of the feet when it is at full contact with the ground) of a character walking on an uneven terrain. Used in combination with the shrinkwrap constraint, I think this would make for ease in making a character walk naturally on rough ground if the use of paths is undesired (besides, I attempted controlling the base orientation of a moving character's feet using a path that was shrink-wrapped to the shape of the terrain, but it didn't turn out perfect).

It should also reduce certain complexities most people go through when using paths to animate movement (create a cube, parent the cube to the path, reset the position of the cube to start near the beginning of the path, parent the character to the cube and then animate the path -- which I think is less intuitive than simply animating the character, rather than the path).

Furthermore, it will work nicely hand in hand with path following. If a character translates along a path which is aligned to the surface of an uneven terrain, the "Track To Normal" constraint will then be an easy setup responsible for controlling the base orientation of the character's feet.