jQuery bookmarklet

jQuerify++

(function () {
    var el = document.createElement('div'),
        b = document.getElementsByTagName('body')[0];
    otherlib = false, msg = '';
    el.style.position = 'fixed';
    el.style.height = '32px';
    el.style.width = '220px';
    el.style.marginLeft = '-110px';
    el.style.top = '0';
    el.style.left = '50%';
    el.style.padding = '5px 10px';
    el.style.zIndex = 1001;
    el.style.fontSize = '12px';
    el.style.color = '#222';
    el.style.backgroundColor = '#f99';
    if (typeof jQuery != 'undefined') {
        msg = 'This page already using jQuery v' + jQuery.fn.jquery;
        return showMsg();
    } else if (typeof $ == 'function') {
        otherlib = true;
    }
    function getScript(url, success) {
        var script = document.createElement('script');
        script.src = url;
        var head = document.getElementsByTagName('head')[0],
            done = false;
        script.onload = script.onreadystatechange = function () {
            if (!done && (!this.readyState || this.readyState == 'loaded' || this.readyState == 'complete')) {
                done = true;
                success();
                script.onload = script.onreadystatechange = null;
                head.removeChild(script);
            }
        };
        head.appendChild(script);
    }
    getScript('http://code.jquery.com/jquery-latest.min.js', function () {
        if (typeof jQuery == 'undefined') {
            msg = 'Sorry, but jQuery wasn\'t able to load';
        } else {
            msg = 'This page is now jQuerified with v' + jQuery.fn.jquery;
            if (otherlib) {
                msg += ' and noConflict(). Use $jq(), not $().';
            }
        }
        return showMsg();
    });

    function showMsg() {
        el.innerHTML = msg;
        b.appendChild(el);
        window.setTimeout(function () {
            if (typeof jQuery == 'undefined') {
                b.removeChild(el);
            } else {
                jQuery(el).fadeOut('slow', function () {
                    jQuery(this).remove();
                });
                if (otherlib) {
                    $jq = jQuery.noConflict();
                }
            }
        }, 2500);
    }
})();