I have been using colorbox and for over a year now as a "popup" for my clients sites like this:
<div id='form-popup'> <div id='form'> <?php echo do_shortcode('[gravityform id="2" name="Inquiry about this item" title="false" description="false" ajax="true"]'); ?> </div> </div>
updated gravity forms today, url:
"inquire about this item" does not work.
version 1.6.2, works fine, url for a client