I have no idea if this exists, but I'll give it a shot. in GNOME (specifically on Ubuntu, but i believe this persists), you can right click on a panel, and toggle "expand" which centralizes the panel to just the length it needs to be. This looks great when your active programs aren't running.
But when you have a program maximized, there are two openings in the top corners where you can see your background. I find it disturbing.
Is there any way to configure it so that on maximize of a program, the panel will "expand"? maybe a shell command? thanks.