This gem of a site details how to mod Firefox to take full advantage of the screenspace available today’s widescreen displays. You’ll need to install the TabMix Plus extension, and drop in the author’s userChrome.css in your /.mozilla/ /chrome/ file. This is by far one of coolest and most useful userChrome.css modifications I’ve seen.

How do you switch things up in your Firefox userChrome.css file?

[Edit - Here's the link!]
Full Story: Widefox