Is there a native jQuery function to switch elements?

Paulo's right, but I'm not sure why he's cloning the elements concerned. This isn't really necessary and will lose any references or event listeners associated with the elements and their descendants.

Here's a non-cloning version using plain DOM methods (since jQuery doesn't really have any special functions to make this particular operation easier):

function swapNodes(a, b) {
    var aparent = a.parentNode;
    var asibling = a.nextSibling === b ? a : a.nextSibling;
    b.parentNode.insertBefore(a, b);
    aparent.insertBefore(b, asibling);
}

No, there isn't, but you could whip one up:

jQuery.fn.swapWith = function(to) {
    return this.each(function() {
        var copy_to = $(to).clone(true);
        var copy_from = $(this).clone(true);
        $(to).replaceWith(copy_from);
        $(this).replaceWith(copy_to);
    });
};

Usage:

$(selector1).swapWith(selector2);

Note this only works if the selectors only match 1 element each, otherwise it could give weird results.

You shouldn't need two clones, one will do. Taking Paolo Bergantino answer we have:

jQuery.fn.swapWith = function(to) {
    return this.each(function() {
        var copy_to = $(to).clone(true);
        $(to).replaceWith(this);
        $(this).replaceWith(copy_to);
    });
};

Should be quicker. Passing in the smaller of the two elements should also speed things up.

I've made a function which allows you to move multiple selected options up or down

$('#your_select_box').move_selected_options('down');
$('#your_select_boxt').move_selected_options('up');

Dependencies:

$.fn.reverse = [].reverse;
function swapWith() (Paolo Bergantino)

First it checks whether the first/last selected option is able to move up/down. Then it loops through all the elements and calls

swapWith(element.next() or element.prev())

jQuery.fn.move_selected_options = function(up_or_down) {
  if(up_or_down == 'up'){
      var first_can_move_up = $("#" + this.attr('id') + ' option:selected:first').prev().size();
      if(first_can_move_up){
          $.each($("#" + this.attr('id') + ' option:selected'), function(index, option){
              $(option).swapWith($(option).prev());
          });
      }
  } else {
      var last_can_move_down = $("#" + this.attr('id') + ' option:selected:last').next().size();
      if(last_can_move_down){
        $.each($("#" + this.attr('id') + ' option:selected').reverse(), function(index, option){
            $(option).swapWith($(option).next());
        });
      }
  }
  return $(this);
}

$('.five').swap('.two');

Create a jQuery function like this

$.fn.swap = function (elem) 
{
    elem = elem.jquery ? elem : $(elem);
    return this.each(function () 
    {
        $('<span></span>').insertBefore(this).before(elem.before(this)).remove();
    });
};

Thanks to Yannick Guinness at https://jsfiddle.net/ARTsinn/TVjnr/

No need to use jquery for any major browser to swap elements at the moment. Native dom method, insertAdjacentElement does the trick no matter how they are located:

var el1 = $("el1");
var el2 = $("el2");
el1[0].insertAdjacentElement("afterend", el2[0]);

The best option is to clone them with clone() method.