yeah, people make these images, they don't just appear out of thin air. Xulas is different though, I have one like that for Xtremesystems folding where it has my daily fold numbers and whatnot, but that's completely different.
Get your image hosted and use the normal [ img ] and [ / img ] tags, of course no spaces in between with the URL to the image in between
EDIT: lol I see in the 2 seconds that I typed this up Xulas sig changed