image galleries for posting images we want to store on server for comments

It occurred to me that we might have an image gallery where we can post (via the attachment method) images. That way, if we had them on the server, even if they weren't promoted to the front page or even published on our blogs, they would have a url, and we could add them into comments. Currently it is my undertanding that we can't attach image files to comments. Would this be possible?