Several years ago I dreamed up a tool that would do for layout and website problems what Talkback was doing for stability problems; allow us to identify and attack the worst problems first.
Thanks a million to Robert Accettura who made it a reality and to all of the others who helped us get this into the tree (hopefully) in time for Deer Park Alpha.
If you're on Windows, you can get a sneak peek tonight by downloadsing one of these builds.
The tool, called "Reporter", is accessible from the Help menu and launches a simple wizard that lets you send us feedback about broken websites. It's not yet a part of the default installer, but you can enable it by doing a custom installation and checking the box in the list of available additions (with DOM Inspector and Talkback.)
Starting tomorrow it should be a part of all of the trunk nightly Firefox builds (though still an install time option for now). Please give it a whirl, report some broken websites, and let me know if it works for you.