XP Customization
PatchXP patches Windows to let you use non-Microsoft themes
http://www.belchfire.net/article205.html
tgtsoft sells Style XP
http://www.tgtsoft.com/
An easy tutorial on modifying your boot and login screens is at http://www.extrememhz.com/winxpcust-p2.shtml
Some cool themes available from http://www.lightstar1.com/ complete with FAQs on how to install them.
