But now I work on Ubuntu machines. And I get big, confused window placement. But I see a way out.
Window Selector. You can know what the current window in focus is.
wmctrl. You can tell it to move or resize a window, and it does it. From the command line, so it might as well be from anywhere.
So, given that each of these things is doable, it should be doable to take A) the current window in focus and B) tell Gnome (or rather Metacity, or whatever WM you use within reason) to move and resize a window to this corner by C) hitting a certain key combination.
But I do not, as of yet, know how to make this happen. But I will post here as I learn.