jquery.spin.js

$.extend($.fn, {
    spin: function (opts, callback) {
        this.each(function() {
            var $this = $(this),
                data = $this.data();

            if (opts !== false) {
                data.spinner = new Spinner(opts).spin(this);

                $this.trigger('spin');

                callback.call($this);
            }
        });
        return this;
    }, // spin (depend from spin.js)

    unspin: function (callback) {
        this.each(function () {
            var $this = $(this),
                data = $this.data();

            if (data.spinner) {
                data.spinner.stop();

                $this.trigger('unspin');

                callback.call($this);

                delete data.spinner;
            }
        });

        return this;
    } // unspin (depend from spin.js)
});