I use a different site to make mine, but I've been doing it for a while, I've made quite a few different ones of me for msn and a couple for other people. heres a few:
They're all ones of me, apart from this one, this one I did for a friend that I happen to like rather a lot [;)] heh heh.
1. Make your image in the program
2. Press "Print Screen" on your keyboard
3. Open up a image program e.g. Paint
4. Press "Paste"
5. Cut wanted part of image out
6. Open a new blank page
7. Paste the cut image in
8. (Resize page if needed)
9. Save the image
Then when you click "Reply to topic" here, select "Insert an Image File"