Fortysomething.ca have a slightly different than normal Windows XP theme – Royale Noir.
UPDATE: Please note that the freely available Zune theme is very similar (and feels a lot more finished than this theme.
It’s not perfect – some bits like the scrollbars are still standard blue Royale, but it makes a change for those becoming-dangerously-rare times when I’m in Windows (without hacking uxtheme.dll).
And the reason you don’t have to hack that file is because this is an official signed theme by Microsoft – albeit one they hadn’t finished and didn’t intend to publish.
Yes, I’m slow to this. I saw it on Digg about a week ago and I downloaded it, unrared it and put it on my shared partition, but didn’t get round to actually installing it in Windows until now. 7-Zip will unrar it for you, don’t get WinRAR, it’s arguably evil (I shouldn’t have to pay to decompress files, it’s just ridiculous).