I have two monitors and I wish I had room for a third. I often use several applications simultaenously which interact with each other, and some of my programs have so many palettes that I wouldn't have any workspace left if I kept them all on my main monitor.
I have a nice little image on my desktop. I see it each time I minimize a program. It's a bit like the pictures on my walls. I don't spend time staring at them but I would miss them if they weren't there.
But when I have decided on a picture, on my walls as well as on my desktop, I stick to it for quite a long time