There is a new theme from Microsoft for the Windows XP. The theme is in the style of Zune, that new Mp3 player that Microsoft put out. It is a pretty crummy Mp3 player with all it's DRM'ness, but the theme is still pretty cool. It makes your XP look allot like Vista's aero theme (not the glass one.) Free of course but you must have XP sp2 or higher for the installer. For other versions of XP like mine, x64, you'll have to get the files out of some one's themes folder in a x32 bit version of XP and it will still work.
Here is the page on the Zune site.
Download it directly from Microsoft here.(link working as of 12/06)