There are graphical interfaces for xrandr, which covers all your display/resolution options. There is driconf, which covers mesa options (3D settings). I haven't seen an interface for handling DDX drivers themselves; there are more than a few advanced options for drivers that still require the user to do manual editing of configuration files; these options are usually auto-configured by X depending on your device, so most of the time it "just works" and there is little need for extra tweaking; a GUI for debuging purposes would be useful for some, but then again, if you're trying to fix your driver the last thing you need is a GUI. I agree though, that an all purpose GUI would still be useful. I would love to have a single interface that would link me to my DDX driver's manual and at least list all available options, that integrates one of the xrandr graphical interfaces, includes driconf for mesa cofiguration, and even links me to xorg.conf with a click.