Cacher is the code snippet organizer for pro developers

Example: http://jsfiddle.net/xrd5Y/16/

// number of columns
var columns = 4;

var $ul = $('ul.multicolumn'),
    $elements = $ul.children('li'),
    breakPoint = Math.ceil($elements.length/columns);
    $ordered = $('<div></div>');

function appendToUL(i) {
    if ($ul.children().eq(i).length > 0) {
        $ordered.append($ul.children().eq(i).clone());
    } 
    else $ordered.append($('<li></li>'));
}

function reorder($el) {
    $el.each(function(){
        $item = $(this);

        if ($item.index() >= breakPoint) return false;

        appendToUL($item.index());
        for (var i = 1; i < columns; i++) {
            appendToUL(breakPoint*i+$item.index());
        }
    });

    $ul.html($ordered.children().css('width',100/columns+'%'));
}

reorder($elements);