Sometimes you want to display form errors as a group at the top of a page. You could accomplish it by using HtmlHelper::tagErrorMsg(), but well, such a solution is not very elegant imho. So I wrote a little helper which generates the following HTML code to display errors:
<div class="error-messages">
Please fix the following errors:
<ul>
<li>First error message</li>
<li>Second error message</li>
</ul>
</div>
The usage of the helper is simple. Add it to the helpers array of your controller:
var $helpers = array('Error');
and use it in your view in the following way:
echo $error->showMessages(array('Model' => array('Field1' => 'First error message', 'Field2' => 'Second error message')));
I hope it will be useful for some of you.
Merry Christmas to those who celebrate Christmas!

MMMmmmmm nice…
Hmm i think better solution is to display the errors near the fields (the default approach) – from the usability point of view.
Merry Christmas!
@Kabturek: Yes, you are right. From a usability point of view it is probably not the best solution, at least not for forms with many input fields.