An example of even spreading of li elements (with child li elements) within a set number of columns using jQuery.

evenly_spread.js

$(function(){
        var columns_no = 4;
	$('.popup').each(function(){
		var total_height = $(this).find('li:not(.brands_column li)').length;
		var column = $(this).find('.column1');
		var average_height = Math.ceil(total_height / columns_no);
		column.data('height', 0);
		var total_categories = $(this).find('li.depth1').length;
		$(this).find('li.depth1').each(function(){
			if (total_categories == columns_no) {
				do_append($(this), column)
				column = cycle_column(column);
			} else if (column.data('height') >= average_height) {
				column = cycle_column(column);
				do_append($(this), column);
			} else {
				do_append($(this), column);
			}
		});
	});
});

function do_append(category, column) {
	var cat_height = category.find('li').length;
	var to_add = 1;
	if (cat_height == 1)
		to_add = 2;
	category.appendTo(column);
	column.data('height',column.data('height') + cat_height + to_add);
}

function cycle_column(column) {
	column = column.next();
	column.data('height', 0)
	return column;
}

Visual representation: http://goo.gl/aC0wd