jQuery UI drop event of droppable fires on sortable
$('#sortable').sortable().droppable({
// Drop should only fire when a draggable element is dropped into the sortables,
// and NOT when the sortables themselves are sorted (without something being dragged into).
drop: function(ev, ui){
    $(ui.draggable).html('<div>TEMPLATE</div>');
}
});
$('#draggables li').draggable({
    connectToSortable: '#sortable',
    helper: 'clone',
    revert: 'invalid',
    cursor: 'move'
});​