Here's a point
Because my eyes are sensitive to glare, I use fairly dark, solid-color backgrounds. The Win7 logon and shutdown backgrounds are way too bright for me, so I gave this tip a try.
Works like a charm.
Here's an extra benefit. As the default background, I use the same color as I use for the desktop. The result is a seamless transition from logon, to desktop, to shutdown. The result makes the appearance of Win 7 more elegant than any prior version.
Thanks, Greg.