I'd recommend that you save your render as a TIF, bitmap, or if you're on a Mac, as a pict, and then use an image editor(PSP, PhotoShop, etc.) to convert your image to a .jpeg. Bryce's native .jpeg compression leaves a lot to be desired and I think you'll find that you can really improve the appearance of your uploads if you use another prog to handle the conversion. I almost always use premium, or fine art antialiasing because I find that it can enhance many fine details and textures that might not show up otherwise, but that's just my experience.