I've been looking for a good option as well. Members on some of my clients forums and my own tend to use the url option for images all the time using image hosting sites. Many times these image hosting sites remove the image after a certain amount of time and then the sites end up with a bunch of broken and missing images.
I changed the phrasing a bit on the add an image phrases to try to encourage members to upload instead of posting images by the url but the best option here would be to offer an image hosting option that saves the image right on my server so I know the images will be there for as long as I live.
Seeing as this is an old post has there been any advances on this front?