I'm wrestling with using a background image in the Gravity skin. If I upload it through Site Admin / Appearance / Body Background, I am unable to set it as no-repeat. I've tried to override using the portal css and the skin css "Body" element with "background-image: URL(location/filename); background-repeat: no-repeat;" but the image doesn't show. Some pages on this site are long so it is important to have a no-repeat BG image.
A nice upgrade to this process would be a "no-repeat" radio button in Site Admin/Appearance/Body Background so when the image is placed a no-repeat element is added.