IE conditional comments

Have you ever designed a web page and have it display perfectly in Firefox but not in IE? When all else fails, you can use the IE conditional comments, such as:

<![if IE]>
  <style> .highlightBox {margin-top: 5px } </style>
<![endif]>

More info here: http://msdn.microsoft.com/en-us/library/ms537512.aspx