Version:           KDE <= 4.3 (using KDE 4.2.90)
OS:                Linux
Installed from:    Ubuntu Packages

Well, after the massive work done to make more usable the KDE GUI in the 4.X series, there is one element that did not receive the deserved attention: the directory selector widget that appears in many many programs. 
As examples: (i) amarok for selecting the directories to be used in the collection. (ii) Dolphin, when selecting the home directory. 
As it is now, it is just a tree browser that obliges you to scroll if you have several directories. Worst thing: you see the complete structure from root! 

I think that there is a lot of screen wasted in displaying useless information: If you selected already a directory (and you didn't click the wrong directory) chances are that you do not want to see the complete tree structure upwards; in general the most thing that you need to go up one directory.
Moreover, at the end, the icons are really small, compared to the ones we see now in plasma, which are much more navigable. A better option would be something like the QuickAccess plasmoid, or the like.

All what I said is useful if you want to select just one directory. If (like in amarok) you must select multiple ones, perhaps a list view in  split panel would make it... 

Unfortunately, I am very bad with everything related to image editing/design so I won't try. But I hope this spoils some discussion and ideas.