Change the Logon Screen wallpaper in Vista

you can switch out the blue and green "aura" wallpaper of the logon screen for something more personalized. As with many things in life, there's a hard way and there's an easy way. The easy way is to use the free utility from Stardock that you can download at:
Click Here

You can find instructions for doing it the hard way in a PC Magazine article at:
Click Here