We've created a custom plugin for adding LightBox images to posts. The plugin expects a URL -- not a short link but rather a direct link to an image file (*.png, *.jpg, etc.), so people should be able to add as many images as needed, since they are hosted off-site. Adding multiple images with a shared gallery ID will yield a gallery/slideshow, but single images will work just fine. Be certain to use a unique gallery ID if the image should be viewed as "stand alone".
