Actually, flagrama pm'ed me a way to do it after the forum broke for me once and ended up looking widescreen. This is what he said:
You just have to increase the width of the ".subContentTable" and ".subHeaderTable" classes in the css. They are normally set as 800 some pixels. I used the userContent.css for firefox to do so, but you can probably use anything that will modify the css as well.
In fact, mine is:
@-moz-document domain(zfgc.com)
{
.subContentTable, .subHeaderTable, .contentCellDiv, .contentCell
{
width: 85% !important;
}
}
I can't remember where the usercontent.css file is though, google it