Heard about GridMove a couple of days ago, and downloaded it yesterday.   I've been playing with it since then, and have to say that it is an incredibly useful little utility.  Spent most of the night learning how to make grids so I could get one that works exactly the way I wanted.   Here is what I came up with, in case anyone else is interested...

FYI: It can handle up to 3 monitors, although there are no layouts in it which cross to other monitors (meaning the layouts on monitor 1 only affect monitor 1, etc.).