Sorry – I had a feeling that this could be done with the lightbox plugin prettyPhoto bundled with the theme but could not try this earlier. Here is an example markup that works –
<div id=”inline-1″ class=”hidden”>
<p>This is inline content opened in prettyPhoto.</p>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p></div>
</div>
I am not sure you can see the markup right unless you edit this post. You can see some example here –
http://www.no-margin-for-errors.com/projects/prettyPhoto-jquery-lightbox-clone#prettyPhoto
In the middle of this page, look for the demo named Inline Content. You will need to use the class “hidden” to hide the inline div initially with the theme (the demo uses class named hide).