// ==Bookmarklet==
// @name Test
// @author Peter
// @style data:text/css,imaginary%7Bfont-family%3A%20%22ok%22%7D
// @script https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js
// ==/Bookmarklet==

var $ = jQuery.noConflict(true),
    pCount = $('p').size(),
    divCount = $('div').size(),
    testElement = $('<imaginary>').appendTo('body'),
    testPassed = testElement.css('font-family') == 'ok';
    testElement.remove();

alert('p tags: ' + pCount +
      '\ndiv tags: ' + divCount +
      '\nDid the test element get styled? ' +
      (testPassed ? 'Of course!' : 'Nope.'));