title: jQuery fade elements from one class to another, on hover
body: <p>can this be done?</p>
  
  <p>for eg.</p>
  
  <pre><code>.class1{
    background-image:(whatever.jpg)
    color: #fff;
  }
  
  .class2{
    background-image:(whatever2.jpg)
    color: #999;
  }
  </code></pre>
  
  <p>can I fade all elements that have class1 to class2 when the mouse is over the element, and back to class1 when mouse is out?</p>