ClearLooks For Windows XP | 5 MB
This visual style has a very Linux-y feel to it. That is how it was intended to be, the theme is a port of the Linux theme by the same name. The taskbar is broad compared to the thinner Linux original. The part I found best was the start button, which is completely different from anything windows, and is a welcome change that looks good and goes pretty well with the whole Linux look. The Log Off and Turn Off icons have been changed. The font size is small and complements the visual style.
It has a flat, non-3d, two tone look implemented in a way that would appeal greatly to most users, even those who used to fancy themes. Released under the GPL license, this theme gives you the option of tweaking it as you like. Very Linux!
This updated package includes two versions of the visual style along with Y’z toolbar themes and an xFree cursor set. Certain bugs in the Ubuntu color scheme in previous versions have been fixed. It is a visual style so you will need a third party application like StyleXP to use it.