Topic: The best part of Firefox is:

http://chrispederick.com/work/firefox/webdeveloper/
http://www.iosart.com/firefox/colorzilla/

Want to tinker with the CSS values in the themes? Replacing the images is simple enough, but knowing each style id or class can be a chore to figure out. (Dashboard-->Presentation-->Edit CSS)

I use Firefox most because of the cool tools/extensions. If you have Firefox, and want to tinker with a theme's style, install the webdeveloper tool.