Recently I've been having fun customizing the look of computer stuff I use. I downloaded some new themes for my Pocket PC and the mp3 player on my Pocket PC. Firefox has some nice themes. I downloaded a bunch of them, but this is the one that I'm using now. You may also want to check out Pimpzilla. Here is a guide on how to skin Gmail. I didn't like the stylesheet I downloaded for it, so I think I'll leave it how Google designed it. I would like to customize the look of Windows XP, but there's no good way to do it without buying third party software. So, I downloaded a live cd for Kubuntu, which uses KDE for the desktop environment. KDE has tons of skins and themes. Good times.

Update: Now I'm using this Firefox theme. I think it's pretty slick, and it's related to the KDE project.