A Greasemonkey script that alters the widths of the columns.

google_if_layout_columns.user.js

// ==UserScript==
// @name           Google IG layout columns fixed-fluid-fixed (v4)
// @namespace      artanis_premier
// @description    Widens middle column for more reading space
// @include        http://google.*/ig*
// @include        http://www.google.*/ig*
// ==/UserScript==

var navbar_width = 359;
var col1_width   = 275;
var col2_width   = 275;
var col3_width   = 275;

var base_style = "display:block;padding:0;";

var col1_style = base_style+"width:"+col1_width+"px;";
var col2_style = base_style+"position:absolute; left:"+(parseInt(navbar_width)+12)+"px; right:"+(parseInt(col3_width)+12)+"px; width:auto; min-width:"+col2_width+"px;";
var col3_style = base_style+"float:right; margin:0 12px 0 0; width:"+col3_width+"px;";

document.getElementById('c_1').setAttribute('style', col1_style);
document.getElementById('c_2').setAttribute('style', col2_style);
document.getElementById('c_3').setAttribute('style', col3_style);

//document.getElementById('footerwrap').setAttribute('style', 'display:none;');
//document.createTagByName('div');
//document.getElementById('t_1').appendChild()