Easy entry of dependencies

Hi again,
It’d be great if there were an easy way to set dependencies by item number or by clicking and dragging from one sub-item to another (as you can in Microsoft Project Gannt views). Currently the only way I can see of entering dependencies is to click the + sign and type in the name of the sub-item. And when you have a board with 3000 ish sub-items, it takes a while to search through them (and forget scrolling through the list!).