I had written about the code generated by SpringWidgets not being XHTML compliant.
For users of WordPress I have made available of a plugin that will save you the trouble of figuring out the valid code.
Simply download, install and activate the SpringWidgets plugin.
<?php if (function_exists('echo_springwidgets')) echo_springwidgets(); ?> where you want to display the widget.
As usual you have a lot of customization options available in Options > SpringWidgets
Read more and download the SpringWidgets plugin »