Directory bookmarks for the "Open" tool window.
I am typically working in several different directories and switching back and forth among them. The set of directories that I happen to be working with keeps changing, so I don't want to set them up as Favorites. Since the directories are spread out in different places, it is kind of a pain to have to click around through the tree to get back to the directory you want.
Perhaps there could be some little buttons at the bottom of the "Open" tool window like: "Set 1", "Go to 1", "Set 2", "Go to 2", ...
The "Set" buttons could set the corresponding bookmark at the current directory. The "Go to" buttons would switch to a previously bookmarked directory.
Or if there were no buttons, then maybe some commands that you could bind to keys with the same functionality.