Aloha!! I just donated via PayPal and wanted to let you know this is an awesome Plugin!!
I'm using it with the "Easy FancyBox" plugin. It doesn't work with the image while it's in the "lightbox" but it works just fine from the Post and Page. Love it!!
I've modified the plugin on line 121 in the $pattern variable for a 5th match for the "title" attribute value and then use the "%5$s" on line 117 for the "description" value passed to the Pinterest popup. (also added the $images[$image_count] and params to the $image_tag as needed).
In this way, the Pinterest popup uses the IMG TITLE attribute value instead of the Post Title.
Now I'll have to remember to apply my patch when the plugin updates. Would be awesome if the plugin matched against the IMG TITLE (since it's required by WordPress) instead of using the Post Title for the Pinterest description box.
Mahalo (thanks) again for a great plugin!!
Bare Feet Studios