It would be great to have a simple Pinterest Button at the bottom of the Lightbox to "Pin" the viewed image.
Backlink/URL should be the node, the image is related to
Media(source) should be the URL/Path of the original image (no thumbnail...)
Description could be the node-title

A snippet for the button I use in one simple view looks like this:
<a href="http://pinterest.com/pin/create/button/?url=[path]&media=[field_myimage]&description=...some introduction...: [title] " target="_blank"><img border="0" src="/sites/default/files/images_site/PinExt.png" title="Pin It" alt="Pin It" /></a>

But I don´t know how to get this into Lightbox at the "right place"... so that the button is displayed and the path, field and title could be replaced by the right node-specific things...