Select to (bootstrap) dropdown..

select2dropdown.js

(function($){
    $.fn.select2Dropdown = function(){
        var options = this.find('option'),
            selected = this.find('option:selected').length == 0 
                ? options[0] 
                : this.find('option:selected'),
            div = document.createElement('div'),
            a = document.createElement('a'),
            span = document.createElement('span'),
            ul = document.createElement('ul');

        $(div).addClass('btn-group');
        $(a).addClass('btn dropdown-toggle');
        $(span).addClass('caret');
        $(ul).addClass('dropdown-menu');

        $(ul).append('<li><a href="#">'+ selected.text() +'</a></li>');
        options.each(function(index, item){
            if($(item).val() == $(selected).val()) return true;

            $(ul).append('<li><a href="#">'+ $(item).text() +'</a></li>');
        });

        $(a).html(selected.text() + "&nbsp;")
                .attr('data-toggle','dropdown')
                .attr('href', '#')
                .append(span);

        $(div).append(a);
        $(div).append(ul);

        this.replaceWith($(div));
    };
})(jQuery);