Something very useful with DDO would be the ability to estimate distances, based on the ranks of spot a person has.
With 5 ranks, the distance is would be listed as:
Close - 0-10m
Nigh - 10+-20m
Near - 20+-30m
Far - 30+m.
After 10 ranks, you would be able to judge distances to the nearest 5 meter increments.
After 15 ranks, the increment drops to 1 meter.
After 20 ranks, you get the exact distance between you and your target.
Thoughts?