A cursory search of these forums only seemed to turn up the direction a sketch plane was facing - but what if you wanted to change the direction of the "heading" of a sketch?
I've used other CAD packages that would show arrows indicating the trajectory of a sketch, and you could change that.
An example of the usefulness would be if you wanted to use one sketch to create a thin extrude feature, and realize that you need one of the profiles to go the other way. Currently, you would need to create a new feature that uses that same sketch and choose the profiles you'd like to use. Alternatively, I'll sometimes draw the profile in the opposite way.