I'm trying to render a single still image for print, at a large resolution.  Printed, the single image will be 23 inches by 35 inches, at 200 DPI (it's going to be a poster).  Since this is a huge image, I want to use network rendering (using tile optimization), which is only available by rendering a single-frame animation.

"Render to disk, use an image format such as bmp and it'll render to a numbered series of images, if you have to interrupt the render when you come back tick the skip frames already rendered switch and it'll start from the next frame. Then paste the whole lot together using a video edit package."

Won't work for me.  I only have one frame, which is too large for me to render at a single pass.

"why render an animation at 7600 pixels?? There's no screen that has such a high resolution..."

Because I want to network render a still-image.  Paper has no problem displaying this resolution/dimensions ;)