I would like to see the jump skill implemented if that was possible....it would have an effect on bonuses to climbing and to tumble as well (something like a +2 bonus to tumble checks for every 5 in jump and +2 to jump for every 5 in tumble). If we need to have a ingame sequence for it (not really essential) perhaps something like 'take to the sky' feat that the cleric's bird has but over short distances. Of course it would have penalties for armour and for weight and if it was possible the number of items you're carrying.
Just a thought