Rated 5 out of 5 stars
Works as advertised. One small nit... my bookmark toolbar doesn't have it's bottom border when in the about: screens you modify.http://img819.imageshack.us/img819/9201/capturehvl.png
Problem is due to a Stylish theme I use http://userstyles.org/styles/60468/firefox-australis-mockup-theme I can probably fix it myself.
What platform are you on? Do you have a custom theme?
I'm seeing the border on my Mac and Windows machines, but I'll check into it.