[рони]

Maggie,
можно и зациклить ...

$(document).ready(function() {
    var leftUIEl = $('.carousel-arrow-left');
    var rightUIEl = $('.carousel-arrow-right');
    var elementsList = $('.imageRow');
    var currentLeftValue = 0;
    elementsList.append(elementsList.find('.single')); //без div.set  красивее
    leftUIEl.click(function() {
        currentLeftValue = elementsList.find('.single').eq(1).position().left;
        elementsList.stop().animate({
            left: -currentLeftValue + "px"
        }, 500, function() {
            elementsList.append(elementsList.find('.single').first());
            elementsList.css({
                left: 0
            })
        });

    });

    rightUIEl.click(function() {
        elementsList.prepend(elementsList.find('.single').last());
        currentLeftValue = elementsList.find('.single').eq(1).position().left;
        elementsList.css({
            left: -currentLeftValue + "px"
        })
        elementsList.stop().animate({
            left: 0
        }, 500)
    });

});