Can you get a jpg background to render?  When I import a jpg background then render my scene, the background does not show up unless I export as a jpg. This lessens the quality considerably. Is there a way to use jpg background as a prop? Thanks for your help.

I haven't to complete trick of it, but you use the flat square (terminology will be vague), and make it large enough to be a backdrop. Then go into the part with the 4-armed man (from Da Vinci), and create a jpeg, and use it as a texture for this.

What always gets me is the dimensions of each. If you get the jpeg too small, you get pixillation when applied to the square.

More helpful answers follow this...;)

If your exporting as PNG, most 2D programs will display them with the alpha channel active, which is why your background isn't showing.
Try using TIFF, as most programs deal with the alpha channel in these differently.

I'm curious about your concern that exporting as jpg lessens the quality considerably. Are you, perhaps, unaware that when you export as jpg, there is a prompt that asks you what jpg quality to use? The default is 75, but you should increase that to something between 90 and 100 and you'll see much better quality. Of course, the file size is bigger, which is why you want to choose. Otherwise, it would make sense to export at 100 quality.

The same is true when using cameras. Even expensive digital SLR cameras have a jpg quality setting that lets you trade quality for space. But if you set the camera to use the highest quality, the resulting image is nearly indistinguishable from other formats.

 WOW, thanks for all your input -- I'll try all of them! I needed some suggestions -- and I got them. Thanks again, Pakled, Nruddock and Bagginsbill. 

Bagginsbill, I can only speak from what has happened to me when I rendered then saved my scene as a jpg. Both times the picture came out fuzzy.

If I'm interpreting your post correctly, you are not seeing a background after rendering.  If you are using Poser 7 or Poser Pro, under render settings there is a pull down menu to select render with background.

 Yes, Hborre -- I am using Poser 7, and you are correct in your interpretation of my problem. I'll look for that pull-down. Thanks for your help.

ahmanidjit - that's for Bryce...;)  Same principle in Poser, but the other folks have covered it...