With this funny bug you can use items, which have still cooldown, like Healing Potions.
You need:
2 items of one type, which you can use on yourself(like healing potion)...Item A
1 item you can use on other units(like this wind staff(or w/e)...Item B
1. Use Item A, now the other Item A has cooldown.
2. Use Item B on an unit which is out of range, so that the hero runs towards this unit.
3. While you're running switch the position of the two items.
4. When the hero comes in range to use Item B it uses Item A instead, even if it has still cooldown.
This may be useful if you hero has really low life and you want to heal him quick
tschoerk