I realised that I couldn't get the Dock to fill up the whole of the bottom part of the screen. This isn't irritating, but I find it more UI-ly to get it to do that.
And apparently there hasn't been a hack to this yet. Doh. Can anyone help?
He probably wants to get it to extend right up to the edges.
The reason it doesn't do that is some Carbon or Classic apps still resize windows to full screen height, and without that space off to the right, there would be no way to resize them.