Whoops, nevermind. There's a link near the top of the page that says "Gallery". I've never really used it, so forgot what to do.
You can register in there to set up your own gallery and then upload your images. When you view them, you'll see something under the picture that says "Share this photograph on the message board:" and will have a link you can copy and paste into your message. It even already has the image tags on there for you.