"Your" idea looks more beautiful than what I had in mind. I was thinking of an (optional)small "patch" of colour/box inside each sex that either on its own or with a number on top, it would give you a very quick and relatively (if no number at all) accurate (more accurate) view on the heights/topography.
I was thinking that would be easier to implement than something as expansive as what armored brigade has (I will try a demo one day).
Of course, easier for anyone but me since programming is not my strongest skill.
EDIT: For example something like this (don't laugh with my horrible drawing skills)
http://img212.imageshack.us/img212/7884/hexhv9.jpg