Started a new job recently and decided to make the most of XP by trying some of the tweaks at lifehacker.
What I used:
Miscellaneous Days October Wallpaper - Part of Smashing Magazine's October wallpaper calendars. Designed by Michael Schmidt.
Samurize - For the embedded text, system info, date/time, and email notification.
ObjectDock - For the OSX like dock at the bottom.
B&W Weather Icons - for the ObjectDock weather docklet. Found at www.samurize.com