I recently switched from Xfce to give Gnome a try. There is one tiny thing about the transition that is bothering me. In Xfce, when I used a keyboard shortcut to switch between workspaces, it would simply make the switch. But when I do the same thing in Gnome, it causes a box to appear in the center of the screen showing you all the workspaces. I find this not only annoying, but I think it also makes the process slower and may even be getting in the way when I try to use other keyboard shortcuts quickly after making a workspace switch.

Anyway, does anyone know what setting I would change with the gconf-editor to make the pop-up box go away? There are so many of them...

Why not add a keyboard shortcut ?
You already have Ctrl+Alt+[ left | right | up | down ] so add shortcuts directly to each workspace, i.e. Ctrl + 6 goes direct to workspace 6.
Personally I don't even see the box using Ctrl+Alt+Right etc. Unless I wait for it ...