I'm a fashion and wedding photographer, and I'm currently using your plug-in on my wedding blog at http://www.jessicadonofrioweddings.com .
I love it! I have long been on the search for just such a plug in that would allow me to integrate Pinterest in a far more attractive way than placing a button under every image and disrupting the "flow."
I've customized your plug-in a bit for my needs, and while I have not had the issue that others have mentioned regarding the alignment, the one issue I'm having is that in any post with more than one image, if the images are inserted one after another without a break, when the plug in is activated, the body of those posts disappears.
When I initially installed, all posts with only one image were showing up, and the plug in worked great. But upon further investigation, I noticed that any posts with multiple images weren't showing up at all.
I found a temporary fix for this that works just fine for me : as long as a break is inserted between every image, the post will show back up. It's a bit tedious because the particular photography blog template I use (ProPhoto Blog) has an "insert all" option, so I'm having to manually go back through every one of my old posts and insert line breaks between all my images. I would imagine photographers will be drawn to your plug in, and the template I mentioned is extremely popular, so I thought I'd let you know.
I was also curious : I saw in a previous forum post you made note that you could make the Pinterest pop up pull from any part of the page for the title (but by default is set to insert title.) I do see in the coding on the css where you would alter this, but apologies, I'm not adept enough to know what code I should insert if I would like it to read as "photo by http://www.jessicadonofrioweddings.com" instead of the post title.
Thanks so much!